Method and device for transmitting and receiving harq-ack information in wireless communication system

ABSTRACT

Disclosed are a method and a device for transmitting and receiving HARQ-ACK information in a wireless communication system. A method of transmitting HARQ-ACK information according to one embodiment of the present disclosure may comprise the steps of: receiving, from a base station, configuration information related to a HARQ-ACK report on a multicast physical downlink shared channel (PDSCH), wherein, on the basis of the configuration, an ACK/negative ACK (NACK)-based HARQ-ACK report or a NACK-only-based HARQ-ACK report is configured for each of one or more identifiers configured in a terminal; receiving, from the base station, downlink control information (DCI) including a cyclic redundancy check (CRC) scrambled by a specific identifier form among the one or more identifiers; receiving, from the base station, the multicast PDSCH on the basis of the DCI; and transmitting, to the base station, HARQ-ACK information on the multicast PDSCH on a first physical uplink control channel (PUCCH) on the basis of the NACK-only-based HARQ-ACK report configured for the specific identifier.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of InternationalApplication No. PCT/KR2022/006775, filed on May 11, 2022, which claimsthe benefit of earlier filing date and right of priority to KoreanApplication No. 10-2021-0060584, filed on May 11, 2021, the contents ofwhich are all hereby incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system, andin more detail, relates to a method and an apparatus of transmitting andreceiving HARQ(Hybrid Automatic Repeat and request)-ACK(acknowledgement)information in a wireless communication system.

BACKGROUND

A mobile communication system has been developed to provide a voiceservice while guaranteeing mobility of users. However, a mobilecommunication system has extended even to a data service as well as avoice service, and currently, an explosive traffic increase has causedshortage of resources and users have demanded a faster service, so amore advanced mobile communication system has been required.

The requirements of a next-generation mobile communication system atlarge should be able to support accommodation of explosive data traffic,a remarkable increase in a transmission rate per user, accommodation ofthe significantly increased number of connected devices, very lowEnd-to-End latency and high energy efficiency. To this end, a variety oftechnologies such as Dual Connectivity, Massive Multiple Input MultipleOutput (Massive MIMO), In-band Full Duplex, Non-Orthogonal MultipleAccess (NOMA), Super wideband Support, Device Networking, etc. have beenresearched.

SUMMARY

A technical object of the present disclosure is to provide a method andan apparatus for transmitting one or more HARQ-ACK information throughone or more physical uplink control channels (PUCCHs).

A technical object of the present disclosure is to provide a method andan apparatus for transmitting and receiving ACK/negative (NACK)-basedHARQ-ACK and/or NACK-only based HARQ-ACK for a multicast physicaldownlink shared channel (PDSCH).

A technical object of the present disclosure is to provide a method andan apparatus for configuring a PUCCH when ACK/NACK-based HARQ-ACK and/orNACK-only based HARQ-ACK are configured for multicast PDSCH reception.

The technical objects to be achieved by the present disclosure are notlimited to the above-described technical objects, and other technicalobjects which are not described herein will be clearly understood bythose skilled in the pertinent art from the following description.

A method of transmitting hybrid automatic repeat and request(HARQ)-acknowledgment (ACK) information in a wireless communicationsystem according to an aspect of the present disclosure, the methodperformed by a user equipment (UE) may include: receiving, from a basestation, configuration information related to HARQ-ACK reporting for amulticast physical downlink shared channel (PDSCH), wherein based on theconfiguration information, ACK/NACK (negative ACK) based HARQ-ACKreporting or NACK-only based HARQ-ACK reporting is configured for eachof one or more identifiers configured in the UE; receiving, from thebase station, downlink control information (DCI) with a cyclicredundancy check (CRC) scrambled by a specific identifier among the oneor more identifiers; receiving, from the base station, a multicast PDSCHbased on the DCI; and based on NACK-only based HARQ-ACK reporting beingconfigured for the specific identifier, transmitting, to the basestation, HARQ-ACK information for the multicast PDSCH on a firstphysical uplink control channel (PUCCH).

A method of receiving hybrid automatic repeat and request(HARQ)-acknowledgment (ACK) information in a wireless communicationsystem according to an additional aspect of the present disclosure, themethod performed by a base station may include: transmitting, to a userequipment (UE), configuration information related to HARQ-ACK reportingfor a multicast physical downlink shared channel (PDSCH), wherein basedon the configuration information, ACK/NACK (negative ACK) based HARQ-ACKreporting or NACK-only based HARQ-ACK reporting is configured for eachof one or more identifiers configured in the UE; transmitting, to theUE, downlink control information (DCI) with a cyclic redundancy check(CRC) scrambled by a specific identifier among the one or moreidentifiers; transmitting, to the UE, a multicast PDSCH based on theDCI; and based on NACK-only based HARQ-ACK reporting being configuredfor the specific identifier, receiving, from the UE, HARQ-ACKinformation for the multicast PDSCH on a first physical uplink controlchannel (PUCCH).

According to an embodiment of the present disclosure, when transmittingone or more HARQ-ACKs to one or more PUCCHs, ambiguity can be preventedso that a base station can accurately interpret HARQ-ACK information.

In addition, according to an embodiment of the present disclosure, anACK/NACK-based HARQ-ACK and a NACK-only-based HARQ-ACK may be configuredfor each UE identifier (e.g., RNTI) according to service requirements.

In addition, according to an embodiment of the present disclosure, whenmultiple HARQ-ACKs are transmitted on a PUCCH of the same slot, bymultiplexing, dropping, bundling, or deferring transmission of aplurality of HARQ-ACKs, even when a UE reports a plurality of HARQ-ACKs,a base station can accurately interpret HARQ-ACK information.

Effects achievable by the present disclosure are not limited to theabove-described effects, and other effects which are not describedherein may be clearly understood by those skilled in the pertinent artfrom the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Accompanying drawings included as part of detailed description forunderstanding the present disclosure provide embodiments of the presentdisclosure and describe technical features of the present disclosurewith detailed description.

FIG. 1 illustrates a structure of a wireless communication system towhich the present disclosure may be applied.

FIG. 2 illustrates a frame structure in a wireless communication systemto which the present disclosure may be applied.

FIG. 3 illustrates a resource grid in a wireless communication system towhich the present disclosure may be applied.

FIG. 4 illustrates a physical resource block in a wireless communicationsystem to which the present disclosure may be applied.

FIG. 5 illustrates a slot structure in a wireless communication systemto which the present disclosure may be applied.

FIG. 6 illustrates physical channels used in a wireless communicationsystem to which the present disclosure may be applied and a generalsignal transmission and reception method using them.

FIG. 7 illustrates a method of multiple TRPs transmission in a wirelesscommunication system to which the present disclosure may be applied.

FIG. 8 illustrates a HARQ-ACK process for downlink data in a wirelesscommunication system to which the present disclosure can be applied.

FIG. 9 illustrates a HARQ-ACK transmission and reception procedureaccording to an embodiment of the present disclosure.

FIG. 10 is a diagram illustrating an operation of a UE for a method fortransmitting and receiving HARQ-ACK information according to anembodiment of the present disclosure.

FIG. 11 is a diagram illustrating an operation of a base station for amethod for transmitting and receiving HARQ-ACK information according toan embodiment of the present disclosure.

FIG. 12 illustrates a block diagram of a wireless communication deviceaccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, embodiments according to the present disclosure will bedescribed in detail by referring to accompanying drawings. Detaileddescription to be disclosed with accompanying drawings is to describeexemplary embodiments of the present disclosure and is not to representthe only embodiment that the present disclosure may be implemented. Thefollowing detailed description includes specific details to providecomplete understanding of the present disclosure. However, those skilledin the pertinent art knows that the present disclosure may beimplemented without such specific details.

In some cases, known structures and devices may be omitted or may beshown in a form of a block diagram based on a core function of eachstructure and device in order to prevent a concept of the presentdisclosure from being ambiguous.

In the present disclosure, when an element is referred to as being“connected”, “combined” or “linked” to another element, it may includean indirect connection relation that yet another element presentstherebetween as well as a direct connection relation. In addition, inthe present disclosure, a term, “include” or “have”, specifies thepresence of a mentioned feature, step, operation, component and/orelement, but it does not exclude the presence or addition of one or moreother features, stages, operations, components, elements and/or theirgroups.

In the present disclosure, a term such as “first”, “second”, etc. isused only to distinguish one element from other element and is not usedto limit elements, and unless otherwise specified, it does not limit anorder or importance, etc. between elements. Accordingly, within a scopeof the present disclosure, a first element in an embodiment may bereferred to as a second element in another embodiment and likewise, asecond element in an embodiment may be referred to as a first element inanother embodiment.

A term used in the present disclosure is to describe a specificembodiment, and is not to limit a claim. As used in a described andattached claim of an embodiment, a singular form is intended to includea plural form, unless the context clearly indicates otherwise. A termused in the present disclosure, “and/or”, may refer to one of relatedenumerated items or it means that it refers to and includes any and allpossible combinations of two or more of them. In addition, “/” betweenwords in the present disclosure has the same meaning as “and/or”, unlessotherwise described.

The present disclosure describes a wireless communication network or awireless communication system, and an operation performed in a wirelesscommunication network may be performed in a process in which a device(e.g., a base station) controlling a corresponding wirelesscommunication network controls a network and transmits or receives asignal, or may be performed in a process in which a terminal associatedto a corresponding wireless network transmits or receives a signal witha network or between terminals.

In the present disclosure, transmitting or receiving a channel includesa meaning of transmitting or receiving information or a signal through acorresponding channel. For example, transmitting a control channel meansthat control information or a control signal is transmitted through acontrol channel. Similarly, transmitting a data channel means that datainformation or a data signal is transmitted through a data channel.

Hereinafter, a downlink (DL) means a communication from a base stationto a terminal and an uplink (UL) means a communication from a terminalto a base station. In a downlink, a transmitter may be part of a basestation and a receiver may be part of a terminal. In an uplink, atransmitter may be part of a terminal and a receiver may be part of abase station. A base station may be expressed as a first communicationdevice and a terminal may be expressed as a second communication device.A base station (BS) may be substituted with a term such as a fixedstation, a Node B, an eNB(evolved-NodeB), a gNB(Next Generation NodeB),a BTS(base transceiver system), an Access Point(AP), a Network(5Gnetwork), an AI(Artificial Intelligence) system/module, an RSU(road sideunit), a robot, a drone(UAV: Unmanned Aerial Vehicle), an AR(AugmentedReality) device, a VR(Virtual Reality) device, etc. In addition, aterminal may be fixed or mobile, and may be substituted with a term suchas a UE(User Equipment), an MS(Mobile Station), a UT(user terminal), anMSS(Mobile Subscriber Station), an SS(Subscriber Station), anAMS(Advanced Mobile Station), a WT(Wireless terminal), anMTC(Machine-Type Communication) device, an M2M(Machine-to-Machine)device, a D2D(Device-to-Device) device, a vehicle, an RSU(road sideunit), a robot, an AI(Artificial Intelligence) module, a drone(UAV:Unmanned Aerial Vehicle), an AR(Augmented Reality) device, a VR(VirtualReality) device, etc.

The following description may be used for a variety of radio accesssystems such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may beimplemented by a wireless technology such as UTRA(Universal TerrestrialRadio Access) or CDMA2000. TDMA may be implemented by a radio technologysuch as GSM(Global System for Mobile communications)/GPRS(General PacketRadio Service)/EDGE(Enhanced Data Rates for GSM Evolution). OFDMA may beimplemented by a radio technology such as IEEE 802.11(Wi-Fi), IEEE802.16(WiMAX), IEEE 802-20, E-UTRA(Evolved UTRA), etc. UTRA is a part ofa UMTS(Universal Mobile Telecommunications System). 3GPP(3rd GenerationPartnership Project) LTE(Long Term Evolution) is a part of anE-UMTS(Evolved UMTS) using E-UTRA and LTE-A(Advanced)/LTE-A pro is anadvanced version of 3GPP LTE. 3GPP NR(New Radio or New Radio AccessTechnology) is an advanced version of 3GPP LTE/LTE-A/LTE-A pro.

To clarify description, it is described based on a 3GPP communicationsystem (e.g., LTE-A, NR), but a technical idea of the present disclosureis not limited thereto. LTE means a technology after 3GPP TS(TechnicalSpecification) 36.xxx Release 8. In detail, an LTE technology in orafter 3GPP TS 36.xxx Release 10 is referred to as LTE-A and an LTEtechnology in or after 3GPP TS 36.xxx Release 13 is referred to as LTE-Apro. 3GPP NR means a technology in or after TS 38.xxx Release 15. LTE/NRmay be referred to as a 3GPP system. “xxx” means a detailed number for astandard document. LTE/NR may be commonly referred to as a 3GPP system.For a background art, a term, an abbreviation, etc. used to describe thepresent disclosure, matters described in a standard document disclosedbefore the present disclosure may be referred to. For example, thefollowing document may be referred to.

For 3GPP LTE, TS 36.211(physical channels and modulation), TS36.212(multiplexing and channel coding), TS 36.213(physical layerprocedures), TS 36.300(overall description), TS 36.331(radio resourcecontrol) may be referred to.

For 3GPP NR, TS 38.211(physical channels and modulation), TS38.212(multiplexing and channel coding), TS 38.213(physical layerprocedures for control), TS 38.214(physical layer procedures for data),TS 38.300(NR and NG-RAN(New Generation-Radio Access Network) overalldescription), TS 38.331(radio resource control protocol specification)may be referred to.

Abbreviations of terms which may be used in the present disclosure isdefined as follows.

BM: beam management

CQI: Channel Quality Indicator

CRI: channel state information-reference signal resource indicator

CSI: channel state information

CSI-IM: channel state information-interference measurement

CSI-RS: channel state information reference signal

DMRS: demodulation reference signal

FDM: frequency division multiplexing

FFT: fast Fourier transform

IFDMA: interleaved frequency division multiple access

IFFT: inverse fast Fourier transform

L1-RSRP: Layer 1 reference signal received power

L1-RSRQ: Layer 1 reference signal received quality

MAC: medium access control

NZP: non-zero power

OFDM: orthogonal frequency division multiplexing

PDCCH: physical downlink control channel

PDSCH: physical downlink shared channel

PMI: precoding matrix indicator

RE: resource element

RI: Rank indicator

RRC: radio resource control

RSSI: received signal strength indicator

Rx: Reception

QCL: quasi co-location

SINR: signal to interference and noise ratio

SSB (or SS/PBCH block): Synchronization signal block (including PSS(primary synchronization signal), SSS (secondary synchronization signal)and PBCH (physical broadcast channel))

TDM: time division multiplexing

TRP: transmission and reception point

TRS: tracking reference signal

Tx: transmission

UE: user equipment

ZP: zero power

Overall System

As more communication devices have required a higher capacity, a needfor an improved mobile broadband communication compared to the existingradio access technology (RAT) has emerged. In addition, massive MTC(Machine Type Communications) providing a variety of services anytimeand anywhere by connecting a plurality of devices and things is also oneof main issues which will be considered in a next-generationcommunication. Furthermore, a communication system design considering aservice/a terminal sensitive to reliability and latency is alsodiscussed. As such, introduction of a next-generation RAT consideringeMBB(enhanced mobile broadband communication), mMTC(massive MTC),URLLC(Ultra-Reliable and Low Latency Communication), etc. is discussedand, for convenience, a corresponding technology is referred to as NR inthe present disclosure. NR is an expression which represents an exampleof a 5G RAT.

A new RAT system including NR uses an OFDM transmission method or atransmission method similar to it. A new RAT system may follow OFDMparameters different from OFDM parameters of LTE. Alternatively, a newRAT system follows a numerology of the existing LTE/LTE-A as it is, butmay support a wider system bandwidth (e.g., 100MHz). Alternatively, onecell may support a plurality of numerologies. In other words, terminalswhich operate in accordance with different numerologies may coexist inone cell.

A numerology corresponds to one subcarrier spacing in a frequencydomain. As a reference subcarrier spacing is scaled by an integer N, adifferent numerology may be defined.

FIG. 1 illustrates a structure of a wireless communication system towhich the present disclosure may be applied.

In reference to FIG. 1 , NG-RAN is configured with gNBs which provide acontrol plane (RRC) protocol end for a NG-RA(NG-Radio Access) user plane(i.e., a new AS(access stratum) sublayer/PDCP(Packet Data ConvergenceProtocol)/RLC(Radio Link Control)/MAC/PHY) and UE. The gNBs areinterconnected through a Xn interface. The gNB, in addition, isconnected to an NGC(New Generation Core) through an NG interface. Inmore detail, the gNB is connected to an AMF(Access and MobilityManagement Function) through an N2 interface, and is connected to aUPF(User Plane Function) through an N3 interface.

FIG. 2 illustrates a frame structure in a wireless communication systemto which the present disclosure may be applied.

A NR system may support a plurality of numerologies. Here, a numerologymay be defined by a subcarrier spacing and a cyclic prefix (CP)overhead. Here, a plurality of subcarrier spacings may be derived byscaling a basic (reference) subcarrier spacing by an integer N (or, μ).In addition, although it is assumed that a very low subcarrier spacingis not used in a very high carrier frequency, a used numerology may beselected independently from a frequency band. In addition, a variety offrame structures according to a plurality of numerologies may besupported in a NR system.

Hereinafter, an OFDM numerology and frame structure which may beconsidered in a NR system will be described. A plurality of OFDMnumerologies supported in a NR system may be defined as in the followingTable 1.

TABLE 1 μ Δf = 2^(μ) · 15 [kHz] CP 0 15 Normal 1 30 Normal 2 60 Normal,Extended 3 120 Normal 4 240 Normal

NR supports a plurality of numerologies (or subcarrier spacings (SCS))for supporting a variety of 5G services. For example, when a SCS is 15kHz, a wide area in traditional cellular bands is supported, and when aSCS is 30 kHz/60 kHz, dense-urban, lower latency and a wider carrierbandwidth are supported, and when a SCS is 60 kHz or higher, a bandwidthwider than 24.25 GHz is supported to overcome a phase noise.

An NR frequency band is defined as a frequency range in two types (FR1,FR2). FR1, FR2 may be configured as in the following Table 2. Inaddition, FR2 may mean a millimeter wave (mmW).

TABLE 2 Frequency Range Corresponding Subcarrier designation frequencyrange Spacing FR1  410 MHz-7125 MHz 15, 30, 60 kHz FR2 24250 MHz-52600MHz 60, 120, 240 kHz

Regarding a frame structure in an NR system, a size of a variety offields in a time domain is expresses as a multiple of a time unit ofT_(c)=1/(Δf_(max)·N_(f)). Here, Δf_(max) is 480·103 Hz and N_(f) is4096. Downlink and uplink transmission is configured (organized) with aradio frame having a duration of T_(f)=1/(Δf_(max)N_(f)/100)·T_(c)=10ms. Here, a radio frame is configured with 10 subframes having aduration of T_(sf)=(Δf_(max)N_(f)/1000)·T_(c)=1 ms, respectively. Inthis case, there may be one set of frames for an uplink and one set offrames for a downlink. In addition, transmission in an uplink frame No.i from a terminal should start earlier byT_(TA)=(N_(TA)+N_(TA,offset))T_(c) than a corresponding downlink framein a corresponding terminal starts. For a subcarrier spacingconfiguration p, slots are numbered in an increasing order of n_(s) ^(μ)∈{0, . . . , N_(slot) ^(subframe,μ)-1} in a subframe and are numbered inan increasing order of n_(s,fP) ^(μ)∈{0, . . . , N_(slot) ^(frame,μ)-1}in a radio frame. One slot is configured with N_(symb) ^(slot)consecutive OFDM symbols and N_(symb) ^(slot) is determined according toCP. A start of a slot n_(s) ^(μ) in a subframe is temporally arrangedwith a start of an OFDM symbol n_(s) ^(μ)N_(symb) ^(slot) in the samesubframe. All terminals may not perform transmission and reception atthe same time, which means that all OFDM symbols of a downlink slot oran uplink slot may not be used.

Table 3 represents the number of OFDM symbols per slot (N_(symb)^(slot)), the number of slots per radio frame (N_(slot) ^(frame,μ)) andthe number of slots per subframe (N_(slot) ^(frame,μ)) in a normal CPand Table 4 represents the number of OFDM symbols per slot, the numberof slots per radio frame and the number of slots per subframe in anextended CP.

TABLE 3 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

TABLE 4 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)2 12 40 4

FIG. 2 is an example on μ=2 (SCS is 60 kHz), 1 subframe may include 4slots referring to Table 3. 1 subframe={1,2,4} slot shown in FIG. 2 isan example, the number of slots which may be included in 1 subframe isdefined as in Table 3 or Table 4. In addition, a mini-slot may include2, 4 or 7 symbols or more or less symbols.

Regarding a physical resource in a NR system, an antenna port, aresource grid, a resource element, a resource block, a carrier part,etc. may be considered. Hereinafter, the physical resources which may beconsidered in an NR system will be described in detail.

First, in relation to an antenna port, an antenna port is defined sothat a channel where a symbol in an antenna port is carried can beinferred from a channel where other symbol in the same antenna port iscarried. When a large-scale property of a channel where a symbol in oneantenna port is carried may be inferred from a channel where a symbol inother antenna port is carried, it may be said that 2 antenna ports arein a QC/QCL(quasi co-located or quasi co-location) relationship. In thiscase, the large-scale property includes at least one of delay spread,doppler spread, frequency shift, average received power, receivedtiming.

FIG. 3 illustrates a resource grid in a wireless communication system towhich the present disclosure may be applied.

In reference to FIG. 3 , it is illustratively described that a resourcegrid is configured with N_(RB) ^(μ)N_(sc) ^(RB) subcarriers in afrequency domain and one subframe is configured with 14·2^(μ) OFDMsymbols, but it is not limited thereto. In an NR system, a transmittedsignal is described by OFDM symbols of 2^(μ)N_(symb) ^((μ)) and one ormore resource grids configured with N_(RB) ^(μ)N_(sc) ^(RB) subcarriers.Here, N_(RB) ^(μ)≤N_(RB) ^(max,μ). The N_(RB) ^(max,μ) represents amaximum transmission bandwidth, which may be different between an uplinkand a downlink as well as between numerologies. In this case, oneresource grid may be configured per μ and antenna port p. Each elementof a resource grid for p and an antenna port p is referred to as aresource element and is uniquely identified by an index pair (k,1′).Here, k=0, . . . , N_(RB) ^(μ)N_(sc) ^(RB)-1 is an index in a frequencydomain and 1′=0, . . . , 2 ^(μ)N_(symb) ^((μ))-1 refers to a position ofa symbol in a subframe. When referring to a resource element in a slot,an index pair (k,1) is used. Here, 1=0, . . . , N_(symb) ^(μ)-1. Aresource element (k,1′) for μ and an antenna port p corresponds to acomplex value, a_(k,1′) ^((p,μ)). When there is no risk of confusion orwhen a specific antenna port or numerology is not specified, indexes pand μ may be dropped, whereupon a complex value may be a_(k,1′) ^((p))or a_(k,1′). In addition, a resource block (RB) is defined as N_(sc)^(RB)=12 consecutive subcarriers in a frequency domain.

Point A plays a role as a common reference point of a resource blockgrid and is obtained as follows.

offsetToPointA for a primary cell (PCell) downlink represents afrequency offset between point A and the lowest subcarrier of the lowestresource block overlapped with a SS/PBCH block which is used by aterminal for an initial cell selection. It is expressed in resourceblock units assuming a 15 kHz subcarrier spacing for FR1 and a 60 kHzsubcarrier spacing for FR2.

absoluteFrequencyPointA represents a frequency-position of point Aexpressed as in ARFCN (absolute radio-frequency channel number).

Common resource blocks are numbered from 0 to the top in a frequencydomain for a subcarrier spacing configuration μ. The center ofsubcarrier 0 of common resource block 0 for a subcarrier spacingconfiguration μ is identical to ‘point A’. A relationship between acommon resource block number n_(CRB) ^(μ) and a resource element (k,1)for a subcarrier spacing configuration p in a frequency domain is givenas in the following Equation 1.

$\begin{matrix}{n_{CRB}^{\mu} = \left\lfloor \frac{k}{N_{sc}^{RB}} \right\rfloor} & \left\lbrack {{Equation}1} \right\rbrack\end{matrix}$

In Equation 1, k is defined relatively to point A so that k=0corresponds to a subcarrier centering in point A. Physical resourceblocks are numbered from 0 to N_(BWP,i) ^(size,μ)-1 in a bandwidth part(BWP) and i is a number of a BWP. A relationship between a physicalresource block n_(PRB) and a common resource block n_(CRB) in BWP i isgiven by the following Equation 2.

n _(CRB) ^(μ) =n _(PRB) ^(μ) +N _(BWP,i) ^(start,μ)  [Equation 2]

N_(BWP,i) ^(start,μ) is a common resource block that a BWP startsrelatively to common resource block 0.

FIG. 4 illustrates a physical resource block in a wireless communicationsystem to which the present disclosure may be applied. And, FIG. 5illustrates a slot structure in a wireless communication system to whichthe present disclosure may be applied.

In reference to FIG. 4 and FIG. 5 , a slot includes a plurality ofsymbols in a time domain. For example, for a normal CP, one slotincludes 7 symbols, but for an extended CP, one slot includes 6 symbols.

A carrier includes a plurality of subcarriers in a frequency domain. AnRB (Resource Block) is defined as a plurality of (e.g., 12) consecutivesubcarriers in a frequency domain. A BWP(Bandwidth Part) is defined as aplurality of consecutive (physical) resource blocks in a frequencydomain and may correspond to one numerology (e.g., an SCS, a CP length,etc.). A carrier may include a maximum N (e.g., 5) BWPs. A datacommunication may be performed through an activated BWP and only one BWPmay be activated for one terminal. In a resource grid, each element isreferred to as a resource element (RE) and one complex symbol may bemapped.

In an NR system, up to 400 MHz may be supported per component carrier(CC). If a terminal operating in such a wideband CC always operatesturning on a radio frequency (FR) chip for the whole CC, terminalbattery consumption may increase. Alternatively, when severalapplication cases operating in one wideband CC (e.g., eMBB, URLLC, Mmtc,V2X, etc.) are considered, a different numerology (e.g., a subcarrierspacing, etc.) may be supported per frequency band in a correspondingCC. Alternatively, each terminal may have a different capability for themaximum bandwidth. By considering it, a base station may indicate aterminal to operate only in a partial bandwidth, not in a full bandwidthof a wideband CC, and a corresponding partial bandwidth is defined as abandwidth part (BWP) for convenience. A BWP may be configured withconsecutive RBs on a frequency axis and may correspond to one numerology(e.g., a subcarrier spacing, a CP length, a slot/a mini-slot duration).

Meanwhile, a base station may configure a plurality of BWPs even in oneCC configured to a terminal. For example, a BWP occupying a relativelysmall frequency domain may be configured in a PDCCH monitoring slot, anda PDSCH indicated by a PDCCH may be scheduled in a greater BWP.Alternatively, when UEs are congested in a specific BWP, some terminalsmay be configured with other BWP for load balancing. Alternatively,considering frequency domain inter-cell interference cancellationbetween neighboring cells, etc., some middle spectrums of a fullbandwidth may be excluded and BWPs on both edges may be configured inthe same slot. In other words, a base station may configure at least oneDL/UL BWP to a terminal associated with a wideband CC. A base stationmay activate at least one DL/UL BWP of configured DL/UL BWP(s) at aspecific time (by L1 signaling or MAC CE(Control Element) or RRCsignaling, etc.). In addition, a base station may indicate switching toother configured DL/UL BWP (by L1 signaling or MAC CE or RRC signaling,etc.). Alternatively, based on a timer, when a timer value is expired,it may be switched to a determined DL/UL BWP. Here, an activated DL/ULBWP is defined as an active DL/UL BWP. But, a configuration on a DL/ULBWP may not be received when a terminal performs an initial accessprocedure or before a RRC connection is set up, so a DL/UL BWP which isassumed by a terminal under these situations is defined as an initialactive DL/UL BWP.

FIG. 6 illustrates physical channels used in a wireless communicationsystem to which the present disclosure may be applied and a generalsignal transmission and reception method using them.

In a wireless communication system, a terminal receives informationthrough a downlink from a base station and transmits information throughan uplink to a base station. Information transmitted and received by abase station and a terminal includes data and a variety of controlinformation and a variety of physical channels exist according to atype/a usage of information transmitted and received by them.

When a terminal is turned on or newly enters a cell, it performs aninitial cell search including synchronization with a base station or thelike (S601). For the initial cell search, a terminal may synchronizewith a base station by receiving a primary synchronization signal (PSS)and a secondary synchronization signal (SSS) from a base station andobtain information such as a cell identifier (ID), etc. After that, aterminal may obtain broadcasting information in a cell by receiving aphysical broadcast channel (PBCH) from a base station. Meanwhile, aterminal may check out a downlink channel state by receiving a downlinkreference signal (DL RS) at an initial cell search stage.

A terminal which completed an initial cell search may obtain moredetailed system information by receiving a physical downlink controlchannel (PDCCH) and a physical downlink shared channel (PDSCH) accordingto information carried in the PDCCH (S602).

Meanwhile, when a terminal accesses to a base station for the first timeor does not have a radio resource for signal transmission, it mayperform a random access (RACH) procedure to a base station (S603 toS606). For the random access procedure, a terminal may transmit aspecific sequence as a preamble through a physical random access channel(PRACH) (S603 and S605) and may receive a response message for apreamble through a PDCCH and a corresponding PDSCH (S604 and S606). Acontention based RACH may additionally perform a contention resolutionprocedure.

A terminal which performed the above-described procedure subsequentlymay perform PDCCH/PDSCH reception (S607) and PUSCH(Physical UplinkShared Channel)/PUCCH(physical uplink control channel) transmission(S608) as a general uplink/downlink signal transmission procedure. Inparticular, a terminal receives downlink control information (DCI)through a PDCCH. Here, DCI includes control information such as resourceallocation information for a terminal and a format varies depending onits purpose of use.

Meanwhile, control information which is transmitted by a terminal to abase station through an uplink or is received by a terminal from a basestation includes a downlink/uplinkACK/NACK(Acknowledgement/Non-Acknowledgement) signal, a CQI(ChannelQuality Indicator), a PMI(Precoding Matrix Indicator), a RI(RankIndicator), etc. For a 3GPP LTE system, a terminal may transmit controlinformation of the above-described CQI/PMI/RI, etc. through a PUSCHand/or a PUCCH.

Table 5 represents an example of a DCI format in an NR system.

TABLE 5 DCI Format Use 0_0 Scheduling of a PUSCH in one cell 0_1Scheduling of one or multiple PUSCHs in one cell, or indication of cellgroup downlink feedback information to a UE 0_2 Scheduling of a PUSCH inone cell 1_0 Scheduling of a PDSCH in one DL cell 1_1 Scheduling of aPDSCH in one cell 1_2 Scheduling of a PDSCH in one cell

In reference to Table 5, DCI formats 0_0, 0_1 and 0_2 may includeresource information (e.g., UL/SUL(Supplementary UL), frequency resourceallocation, time resource allocation, frequency hopping, etc.),information related to a transport block(TB) (e.g., MCS(ModulationCoding and Scheme), a NDI(New Data Indicator), a RV(Redundancy Version),etc.), information related to a HARQ(Hybrid-Automatic Repeat andrequest) (e.g., a process number, a DAI(Downlink Assignment Index),PDSCH-HARQ feedback timing, etc.), information related to multipleantennas (e.g., DMRS sequence initialization information, an antennaport, a CSI request, etc.), power control information (e.g., PUSCH powercontrol, etc.) related to scheduling of a PUSCH and control informationincluded in each DCI format may be pre-defined.

DCI format 0_0 is used for scheduling of a PUSCH in one cell.Information included in DCI format 0_0 is CRC (cyclic redundancy check)scrambled by a C-RNTI(Cell Radio Network Temporary Identifier) or aCS-RNTI(Configured Scheduling RNTI) or a MCS-C-RNTI(Modulation CodingScheme Cell RNTI) and transmitted.

DCI format 01 is used to indicate scheduling of one or more PUSCHs orconfigure grant (CG) downlink feedback information to a terminal in onecell. Information included in DCI format 0_1 is CRC scrambled by aC-RNTI or a CS-RNTI or a SP-CSI-RNTI(Semi-Persistent CSI RNTI) or aMCS-C-RNTI and transmitted.

DCI format 0_2 is used for scheduling of a PUSCH in one cell.Information included in DCI format 0_2 is CRC scrambled by a C-RNTI or aCS-RNTI or a SP-CSI-RNTI or a MCS-C-RNTI and transmitted.

Next, DCI formats 1_0, 1_1 and 1_2 may include resource information(e.g., frequency resource allocation, time resource allocation,VRB(virtual resource block)-PRB(physical resource block) mapping, etc.),information related to a transport block(TB) (e.g., MCS, NDI, RV, etc.),information related to a HARQ (e.g., a process number, DAI, PDSCH-HARQfeedback timing, etc.), information related to multiple antennas (e.g.,an antenna port, a TCI(transmission configuration indicator), aSRS(sounding reference signal) request, etc.), information related to aPUCCH (e.g., PUCCH power control, a PUCCH resource indicator, etc.)related to scheduling of a PDSCH and control information included ineach DCI format may be pre-defined.

DCI format 1_0 is used for scheduling of a PDSCH in one DL cell.Information included in DCI format 1_0 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

DCI format 1_1 is used for scheduling of a PDSCH in one cell.Information included in DCI format 1_1 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

DCI format 1_2 is used for scheduling of a PDSCH in one cell.Information included in DCI format 1_2 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

Quasi-Co Location (QCL)

An antenna port is defined so that a channel where a symbol in anantenna port is transmitted can be inferred from a channel where othersymbol in the same antenna port is transmitted. When a property of achannel where a symbol in one antenna port is carried may be inferredfrom a channel where a symbol in other antenna port is carried, it maybe said that 2 antenna ports are in a QC/QCL(quasi co-located or quasico-location) relationship.

Here, the channel property includes at least one of delay spread,doppler spread, frequency/doppler shift, average received power,received timing/average delay, or a spatial RX parameter. Here, aspatial Rx parameter means a spatial (Rx) channel property parametersuch as an angle of arrival.

A terminal may be configured at list of up to M TCI-State configurationsin a higher layer parameter PDSCH-Config to decode a PDSCH according toa detected PDCCH having intended DCI for a corresponding terminal and agiven serving cell. The M depends on UE capability.

Each TCI-State includes a parameter for configuring a quasi co-locationrelationship between ports of one or two DL reference signals and aDM-RS of a PDSCH.

A quasi co-location relationship is configured by a higher layerparameter qcl-Type1 for a first DL RS and qcl-Type2 for a second DL RS(if configured). For two DL RSs, a QCL type is not the same regardlessof whether a reference is a same DL RS or a different DL RS.

A quasi co-location type corresponding to each DL RS is given by ahigher layer parameter qcl-Type of QCL-Info and may take one of thefollowing values.

‘QCL-TypeA’: {Doppler shift, Doppler spread, average delay, delayspread}

‘QCL-TypeB’: {Doppler shift, Doppler spread}

‘QCL-TypeC’: {Doppler shift, average delay}

‘QCL-TypeD’: {Spatial Rx parameter}

For example, when a target antenna port is a specific NZP CSI-RS, it maybe indicated/configured that a corresponding NZP CSI-RS antenna port(s)is quasi-colocated with a specific TRS with regard to QCL-Type A and isquasi-colocated with a specific SSB with regard to QCL-Type D. Aterminal received such indication/configuration may receive acorresponding NZP CSI-RS by using a doppler, delay value measured in aQCL-TypeA TRS and apply a Rx beam used for receiving QCL-TypeD SSB toreception of a corresponding NZP CSI-RS.

UE may receive an activation command by MAC CE signaling used to map upto 8 TCI states to a codepoint of a DCI field ‘TransmissionConfiguration Indication’.

Operation Related to Multi-TRPs

A coordinated multi point (CoMP) scheme refers to a scheme in which aplurality of base stations effectively control interference byexchanging (e.g., using an X2 interface) or utilizing channelinformation (e.g., RI/CQI/PMI/LI(layer indicator), etc.) fed back by aterminal and cooperatively transmitting to a terminal. According to ascheme used, a CoMP may be classified into joint transmission(JT),coordinated Scheduling(CS), coordinated Beamforming(CB), dynamic PointSelection(DPS), dynamic Point Blocking(DPB), etc.

M-TRP transmission schemes that M TRPs transmit data to one terminal maybe largely classified into i) eMBB M-TRP transmission, a scheme forimproving a transfer rate, and ii) URLLC M-TRP transmission, a schemefor increasing a reception success rate and reducing latency.

In addition, with regard to DCI transmission, M-TRP transmission schemesmay be classified into i) M-TRP transmission based on M-DCI(multipleDCI) that each TRP transmits different DCIs and ii) M-TRP transmissionbased on S-DCI(single DCI) that one TRP transmits DCI. For example, forS-DCI based M-TRP transmission, all scheduling information on datatransmitted by M TRPs should be delivered to a terminal through one DCI,it may be used in an environment of an ideal BackHaul (ideal BH) wheredynamic cooperation between two TRPs is possible.

A UE may recognize PUSCH (or PUCCH) scheduled by DCI received indifferent control resource sets(CORESETs) (or CORESETs belonging todifferent CORESET groups) as PUSCH (or PUCCH) transmitted to differentTRPs or may recognize PDSCH (or PDCCH) from different TRPs. In addition,the below-described method for UL transmission (e.g., PUSCH/PUCCH)transmitted to different TRPs may be applied equivalently to ULtransmission (e.g., PUSCH/PUCCH)transmitted to different panelsbelonging to the same TRP.

Hereinafter, a CORESET group ID described/mentioned in the presentdisclosure may mean an index/identification information (e.g., an ID,etc.) for distinguishing a CORESET for each TRP/panel. In addition, aCORESET group may be a group/union of CORESET distinguished by anindex/identification information (e.g., an ID)/the CORESET group ID,etc. for distinguishing a CORESET for each TRP/panel. In an example, aCORESET group ID may be specific index information defined in a CORESETconfiguration. In this case, a CORESET group may beconfigured/indicated/defined by an index defined in a CORESETconfiguration for each CORESET. Additionally/alternatively, a CORESETgroup ID may mean an index/identification information/an indicator, etc.for distinguishment/identification between CORESETsconfigured/associated with each TRP/panel. Hereinafter, a CORESET groupID described/mentioned in the present disclosure may be expressed bybeing substituted with a specific index/specific identificationinformation/a specific indicator for distinguishment/identificationbetween CORESETs configured/associated with each TRP/panel. The CORESETgroup ID, i.e., a specific index/specific identification information/aspecific indicator for distinguishment/identification between

CORESETs configured/associated with each TRP/panel may beconfigured/indicated to a terminal through higher layer signaling (e.g.,RRC signaling)/L2 signaling (e.g., MAC-CE)/L1 signaling (e.g., DCI),etc. In an example, it may be configured/indicated so that PDCCHdetection will be performed per each TRP/panel in a unit of acorresponding CORESET group (i.e., per TRP/panel belonging to the sameCORESET group). Additionally/alternatively, it may beconfigured/indicated so that uplink control information (e.g., CSI,HARQ-A/N(ACK/NACK), SR(scheduling request)) and/or uplink physicalchannel resources (e.g., PUCCH/PRACH/SRS resources) are separated andmanaged/controlled per each TRP/panel in a unit of a correspondingCORESET group (i.e., per TRP/panel belonging to the same CORESET group).Additionally/alternatively, HARQ A/N(process/retransmission) forPDSCH/PUSCH, etc. scheduled per each TRP/panel may be managed percorresponding CORESET group (i.e., per TRP/panel belonging to the sameCORESET group).

For example, a higher layer parameter, ControlResourceSet informationelement (IE), is used to configure a time/frequency control resource set(CORESET). In an example, the control resource set (CORESET) may berelated to detection and reception of downlink control information. The

ControlResourceSet IE may include a CORESET-related ID (e.g.,controlResourceSetID)/an index of a CORESET pool for a CORESET (e.g.,CORESETPoolIndex)/a time/frequency resource configuration of aCORESET/TCI information related to a CORESET, etc. In an example, anindex of a CORESET pool (e.g., CORESETPoolIndex) may be configured as 0or 1. In the description, a CORESET group may correspond to a CORESETpool and a CORESET group ID may correspond to a CORESET pool index(e.g., CORESETPoolIndex).

Hereinafter, a method for improving reliability in Multi-TRP will bedescribed.

As a transmission and reception method for improving reliability usingtransmission in a plurality of TRPs, the following two methods may beconsidered.

FIG. 7 illustrates a method of multiple TRPs transmission in a wirelesscommunication system to which the present disclosure may be applied.

In reference to FIG. 7(a), it is shown a case in which layer groupstransmitting the same codeword(CW)/transport block(TB) correspond todifferent TRPs. Here, a layer group may mean a predetermined layer setincluding one or more layers. In this case, there is an advantage thatthe amount of transmitted resources increases due to the number of aplurality of layers and thereby a robust channel coding with a lowcoding rate may be used for a TB, and additionally, because a pluralityof TRPs have different channels, it may be expected to improvereliability of a received signal based on a diversity gain.

In reference to FIG. 7(b), an example that different CWs are transmittedthrough layer groups corresponding to different TRPs is shown. Here, itmay be assumed that a TB corresponding to CW #1 and CW #2 in the drawingis identical to each other. In other words, CW #1 and CW #2 mean thatthe same TB is respectively transformed through channel coding, etc.into different CWs by different TRPs. Accordingly, it may be consideredas an example that the same TB is repetitively transmitted. In case ofFIG. 7(b), it may have a disadvantage that a code rate corresponding toa TB is higher compared to FIG. 7(a). However, it has an advantage thatit may adjust a code rate by indicating a different RV (redundancyversion) value or may adjust a modulation order of each CW for encodedbits generated from the same TB according to a channel environment.

According to methods illustrated in FIG. 7(a) and FIG. 7(b) above,probability of data reception of a terminal may be improved as the sameTB is repetitively transmitted through a different layer group and eachlayer group is transmitted by a different TRP/panel. It is referred toas a SDM (Spatial Division Multiplexing) based M-TRP URLLC transmissionmethod. Layers belonging to different layer groups are respectivelytransmitted through DMRS ports belonging to different DMRS CDM groups.

In addition, the above-described contents related to multiple TRPs aredescribed based on an SDM (spatial division multiplexing) method usingdifferent layers, but it may be naturally extended and applied to a FDM(frequency division multiplexing) method based on a different frequencydomain resource (e.g., RB/PRB (set), etc.) and/or a TDM (time divisionmultiplexing) method based on a different time domain resource (e.g., aslot, a symbol, a sub-symbol, etc.).

Multi-TRP scheduled by at least one DCI may be performed as follows:

i) Scheme 1 (SDM): n (n is a natural number) TCI states in a single slotin overlapping time and frequency resource allocation

Scheme 1a: Each transmission occasion is one layer or set of layers ofthe same TB, and each layer or set of layers is associated with one TCIand one set of DMRS port(s). A single codeword with one redundancyversion (RV) is used for all layers or sets of layers. For a UE,different coded bits are mapped to different layers or sets of layerswith specific mapping rules.

Scheme 1b: Each transmission occasion is one layer or set of layers ofthe same TB, and each layer or set of layers is associated with one TCIand one set of DMRS port(s). A single codeword with one RV is used foreach spatial layer or set of layers. RVs corresponding to each spatiallayer or set of layers may be the same or different.

Scheme 1c: Each transmission occasion is one layer of the same TB havingone DMRS port associated with multiple TCI state indices or one layer ofthe same TB with multiple DMRS ports associated with multiple TCIindices in turn (one by one).

In schemes 1a and 1c described above, the same MCS is applied to alllayers or sets of layers.

ii) Scheme 2 (FDM): n (n is a natural number) TCI states in a singleslot in non-overlapping frequency resource allocation. Eachnon-overlapping frequency resource allocation is associated with one TCIstate. The same single/multiple DMRS port(s) is associated with allnon-overlapping frequency resource allocations.

Scheme 2a: A single codeword with one RV is used across an entireresource allocation. For UE, a common RB mapping (mapping of codeword tolayer) is applied across all resource allocations.

Scheme 2b: A single codeword with one RV is used for eachnon-overlapping frequency resource allocation. RVs corresponding to eachnon-overlapping frequency resource allocation may be the same ordifferent.

In scheme 2a, the same MCS is applied to all non-overlapping frequencyresource allocations.

iii) Scheme 3 (TDM): n (n is a natural number) TCI states in a singleslot in non-overlapping time resource allocation. Each transmissionoccasion of a TB has one TCI and one RV with time granularity of amini-slot. All transmission occasion(s) in a slot use a common MCS withthe same single or multiple DMRS port(s). An RV/TCI state may be thesame or different among transmission occasions.

iv) Scheme 4 (TDM): n (n is a natural number) TCI states in K (n<=K, Kis a natural number) different slots. Each transmission occasion of a TBhas one TCI and one RV. All transmission occasion(s) across K slots usea common MCS with the same single or multiple DMRS port(s). An RV/TCIstate may be the same or different among transmission occasions.

Hereinafter, in the present disclosure, DL MTRP-URLLC means that M-TRPstransmit the same data(e.g., transport block, TB)/DCI by using adifferent layer/time/frequency resource. For example, TRP 1 transmitsthe same data/DCI in resource 1 and TRP 2 transmits the same data/DCI inresource 2. UE configured with a DL MTRP-URLLC transmission methodreceives the same data/DCI by using a different layer/time/frequencyresource. Here, UE is indicated which QCL RS/type (i.e., a DL TCI(state)) should be used in a layer/time/frequency resource receiving thesame data/DCI from a base station. For example, when the same data/DCIis received in resource 1 and resource 2, a DL TCI state used inresource 1 and a DL TCI state used in resource 2 may be indicated. UEmay achieve high reliability because it receives the same data/DCIthrough resource 1 and resource 2. Such DL MTRP URLLC may be applied toa PDSCH/a PDCCH.

Conversely, UL MTRP-URLLC means that M-TRPs receive the same data/UCIfrom UE by using a different layer/time/frequency resource. For example,TRP 1 receives the same data/UCI from UE in resource 1 and TRP 2receives the same data/UCI from UE in resource 2 and shares receiveddata/UCI through a backhaul link connected between TRPs. UE configuredwith a UL MTRP-URLLC transmission method transmits the same data/UCI byusing a different layer/time/frequency resource. Here, UE is indicatedwhich Tx beam and which Tx power (i.e., a UL TCI state) should be usedin a layer/time/frequency resource transmitting the same data/DCI from abase station. For example, when the same data/UCI is received inresource 1 and resource 2, a UL TCI state used in resource 1 and a ULTCI state used in resource 2 may be indicated. Such UL MTRP URLLC may beapplied to a PUSCH/a PUCCH.

In addition, in methods proposed in the present disclosure, when aspecific TCI state (or a TCI) is used (/mapped) in receivingdata/DCl/UCI for any frequency/time/space resource, it may mean that aDL estimates a channel from a DMRS by using a QCL type and a QCL RSindicated by a corresponding TCI state in that frequency/time/spaceresource and receives/demodulates data/DCI to an estimated channel. Itmay mean that an UL transmits/modulates a DMRS and data/UCI by using aTx beam and/or Tw power indicated by a corresponding TCI state in thatfrequency/time/space resource.

The UL TCI state has Tx beam and/or Tx power information of UE andspatial relation information, etc. instead of a TCI state may beconfigured to UE through other parameter. An UL TCI state may bedirectly indicated to UL grant DCI or may mean spatial relationinformation of an SRS resource indicated by an SRI (SRS resourceindicator) field of UL grant DCI. Alternatively, it may mean an OL (openloop) Tx power control parameter connected to a value indicated by a SRIfield of UL grant DCI (j: an index for open loop parameter Po andalpha(a) (up to 32 parameter value sets per cell), q_d: an index of a DLRS resource for PL (pathloss) measurement (measurement of up to 3 percell), 1: a closed loop power control process index (up to 2 processesper cell)).

On the other hand, it is assumed that MTRP-eMBB means that M-TRPStransmit other data by using a different layer/time/frequency, UEconfigured with a MTRP-eMBB transmission method is indicated multipleTCI states with DCI and data received by using a QCL RS of each TCIstate is different data.

In addition, whether of MTRP URLLC transmission/reception or MTRP eMBBtransmission/reception may be understood by UE by separately classifyinga RNTI for MTRP-URLLC and a RNTI for MTRP-eMBB and using them. In otherwords, when CRC masking of DCI is performed by using a RNTI for URLLC,it is considered as URLLC transmission and when CRC masking of DCI isperformed by using a RNTI for eMBB, it is considered as eMBBtransmission. Alternatively, a base station may configure MTRP URLLCtransmission/reception or may configure MTRP eMBB transmission/receptionto UE through other new signaling.

In the present disclosure, for convenience of a description, a proposalis applied by assuming cooperative transmission/reception between 2TRPs, but it may be extended and applied in 3 or more multi-TRPenvironments and it may be also extended and applied in multi-panelenvironments. A different TRP may be recognized by UE as a differenttransmission configuration indication (TCI) state. That is, when UEreceives/transmits data/DCl/UCI by using TCI state 1, it means thatdata/DCl/UCI is received/transmitted from/to TRP 1.

A proposal of the present disclosure may be utilized in a situationwhere MTRP cooperatively transmits a PDCCH (the same PDCCH isrepetitively or partitively transmitted) and some proposals may beutilized even in a situation where MTRP cooperatively transmits a PDSCHor cooperatively receives a PUSCH/a PUCCH.

In addition, in the present disclosure below, the meaning that aplurality of base stations (i.e., MTRP) repetitively transmits the samePDCCH may mean the same DCI is transmitted by a plurality of PDCCHcandidates, and it is equivalent with the meaning that a plurality ofbase stations repetitively transmits the same DCI. The same DCI may meantwo DCI with the same DCI format/size/payload. Alternatively, althoughtwo DCI have a different payload, it may be considered the same DCI whena scheduling result is the same. For example, a TDRA (time domainresource allocation) field of DCI relatively determines a slot/symbolposition of data and a slot/symbol position of A/N(ACK/NACK) based on areception time of DCI. Here, if DCI received at a time of n and DCIreceived at a time of n+1 represent the same scheduling result to UE, aTDRA field of two DCI is different, and consequentially, a DCI payloadis different. R, the number of repetitions, may be directly indicated ormutually promised by a base station to UE. Alternatively, although apayload of two DCI is different and a scheduling result is not the same,it may be considered the same DCI when a scheduling result of one DCI isa subset of a scheduling result of other DCI. For example, when the samedata is repetitively transmitted N times through TDM, DCI 1 receivedbefore first data indicates N data repetitions and DCI 2 received afterfirst data and before second data indicates N−1 data repetitions.Scheduling data of DCI 2 becomes a subset of scheduling data of DCI 1and two DCI is scheduling for the same data, so in this case, it may beconsidered the same DCI.

In addition, in the present disclosure below, when a plurality of basestations (i.e., MTRP) divide and transmit the same PDCCH, it may meanthat one DCI is transmitted through one PDCCH candidate, but TRP 1transmits some resources in which the PDCCH candidate is defined and TRP2 transmits the remaining resources. For example, when TRP 1 and TRP 2divide and transmit a PDCCH candidate corresponding to an aggregationlevel m1+m2, the PDCCH candidate is divided into PDCCH candidate 1corresponding to aggregation level m1 and PDCCH candidate 2corresponding to aggregation level m2, and TRP 1 transmits the PDCCHcandidate 1 and TRP 2 transmits the PDCCH candidate 2 using differenttime/frequency resources. After receiving the PDCCH candidate 1 and thePDCCH candidate 2, a UE generates a PDCCH candidate corresponding toaggregation level m1+m2 and attempts

DCI decoding.

When the same DCI is divided and transmitted to several PDCCHcandidates, there may be two implementation methods.

First, a DCI payload (control information bits+CRC) may be encodedthrough one channel encoder (e.g., a polar encoder), coded bits obtainedas a result may be divided into two TRPs and transmitted. In this case,an entire DCI payload may be encoded in coded bits transmitted by eachTRP, or only a part of a DCI payload may be encoded. Second, a DCIpayload (control information bits+CRC) may be divided into two (DCI 1and DCI 2) and each can be encoded through a channel encoder (e.g.,polar encoder). Thereafter, two TRPs may transmit coded bitscorresponding to DCI 1 and coded bits corresponding to DCI 2,respectively.

In summary, it may be as follows that a plurality of base stations(i.e., MTRP) divide/repeat the same PDCCH and transmit over a pluralityof monitoring occasions (MO).

i) it may mean that each base station (i.e., STRP) repeatedly transmitscoded DCI bits obtained by encoding all DCI contents of a correspondingPDCCH through each MO; or,

ii) it may mean that coded DCI bits obtained by encoding all DCIcontents of a corresponding PDCCH are divided into a plurality of parts,and each base station (i.e., STRP) transmits a different part througheach MO; or

iii) it may mean that DCI contents of a corresponding PDCCH are dividedinto a plurality of parts, and each base station (i.e., STRP) separatelyencodes different parts and transmits them through each MO.

That is, it may be understood that a PDCCH is transmitted multiple timesover several transmission occasions (TO) regardless of repeatedtransmission or divided transmission of the PDCCH. Here, a TO means aspecific time/frequency resource unit in which a PDCCH is transmitted.For example, if a PDCCH is transmitted multiple times (in a specificresource block (RB)) over slots 1, 2, 3, and 4, a TO may mean each slot,or if a PDCCH is transmitted multiple times (in a specific slot) over RBsets 1, 2, 3, and 4, a TO may mean each RB set, or if a PDCCH istransmitted multiple times over different times and frequencies, a TOmay mean each time/frequency resource. In addition, a TCI state used forDMRS channel estimation for each TO may be configured differently, andit may be assumed that TOs in which a TCI state is configureddifferently are transmitted by different TRPs/panels. When a pluralityof base stations repeatedly transmits or dividedly transmits a PDCCH, itmeans that the PDCCH is transmitted over a plurality of TOs, and theunion of TCI states configured in corresponding TOs is configured withtwo or more TCI states. For example, if a PDCCH is transmitted over TOs1,2,3,4, TCI states 1,2,3,4 may be configured in each of TOs 1,2,3,4,respectively, which means that TRP i transmits cooperatively a PDCCH inTO i.

For a plurality of TOs indicated to a UE to repeatedly transmit ordividedly transmit a PDCCH/PDSCH/PUSCH/PUCCH, UL transmits to a specificTRP or DL receives from a specific TRP in each TO. Here, a UL TO (or TOof TRP 1) transmitted to TRP 1 means a TO using the first value amongtwo spatial relations, two UL TCIs, two UL power control parametersand/or two pathloss reference signals (PLRS) indicated to a UE, and a ULTO (or TO of TRP 2) transmitted to TRP 2 means a TO using the secondvalue among two spatial relations, two UL TCIs, two UL power controlparameters and/or two PLRSs indicated to a UE. Similarly, for DLtransmission, a DL TO (or TO of TRP 1) transmitted by TRP 1 means a TOusing the first value among two DL TCI states (e.g., when two TCI statesare configured in CORESET) indicated to a UE, and a DL TO (or TO of TRP2) transmitted by TRP 2 means a TO using the second value among two DLTCI states (e.g., when two TCI states are configured in CORESET)indicated to a UE.

The proposal of the present disclosure can be extended and applied tovarious channels such as PUSCH/PUCCH/PDSCH/PDCCH.

The proposal of the present disclosure can be extended and applied toboth a case of repeated transmission and a case of divided transmissionthe channel on different time/frequency/spatial resources.

Data Transmission and HARQ (Hybrid Automatic Repeat and Request)-ACK(Acknowledgement) Process

FIG. 8 illustrates a HARQ-ACK process for downlink data in a wirelesscommunication system to which the present disclosure can be applied.

Referring to FIG. 8 , a UE may detect a PDCCH in slot #n. Here, a PDCCHincludes downlink scheduling information (e.g., DCI formats 1_0 and1_1), and a PDCCH indicates a DL assignment-to-PDSCH offset (K0) and aPDSCH-HARQ-ACK reporting offset (K1). For example, DCI formats 1_0 and1_1 may include the following information.

Frequency domain resource assignment: Indicates an RB resource (e.g.,one or more (dis)contiguous RBs) allocated to a PDSCH

Time domain resource assignment: K0, indicating a start position (e.g.,OFDM symbol index) and a length (e.g., number of OFDM symbols) of aPDSCH in a slot

PDSCH HARQ feedback timing indicator (PDSCH-to-HARQ_feedback timingindicator): Indicates K1

HARQ process number (4 bits): Indicates HARQ process ID (Identity) fordata (e.g., PDSCH, TB)

PUCCH resource indicator (PRI): Indicates a PUCCH resource to be usedfor UCI transmission among a plurality of PUCCH resources in a PUCCHresource set

Thereafter, a UE may receive a PDSCH in slot #(n+KO) according toscheduling information of slot #n, and then transmit UCI through a PUCCHin slot #(n+K1). Here, UCI includes a HARQ-ACK response for a PDSCH. Ifa PDSCH is configured to transmit up to 1 TB, a HARQ-ACK response may becomposed of 1-bit. When a PDSCH is configured to transmit up to two TBs,a HARQ-ACK response may be composed of 2-bits if spatial bundling is notconfigured and 1-bit if spatial bundling is configured. When a HARQ-ACKtransmission time for a plurality of PDSCHs is designated as slot#(n+K1), UCI transmitted in slot #(n+K1) includes HARQ-ACK responses fora plurality of PDSCHs.

Multimedia Broadcast/Multicast Service (MBMS)

3GPP MBMS can be divided into i) a single frequency network (SFN) methodin which a plurality of base station cells are synchronized to transmitthe same data through a physical multicast channel (PMCH) and ii) SC-PTM(Single Cell Point To Multipoint) method broadcasting within a cellcoverage through a PDCCH/PDSCH channel. The SFN method is used toprovide broadcasting services over a wide area (e.g., MBMS area) throughsemi-statically allocated resources, while the SC-PTM method is mainlyused to provide broadcasting services only within a cell coveragethrough dynamic resources.

The SC-PTM provides one logical channel, an SC-MCCH (Single CellMulticast Control Channel) and one or a plurality of logical channels,an SC-MTCH (Single Cell Multicast Traffic Channel). These logicalchannels are mapped to a downlink shared channel (DL-SCH), which is atransport channel, and a PDSCH, which is a physical channel. A PDSCHtransmitting SC-MCCH or SC-MTCH data is scheduled through a PDCCHindicated by a group-RNTI (G-RNTI). In this case, a temporary multicastgroup ID (TMGI) corresponding to a service identifier (ID) may be mappedone-to-one with a specific G-RNTI value. Therefore, if a base stationprovides multiple services, multiple G-RNTI values may be allocated forSC-PTM transmission. One or a plurality of UEs may perform PDCCHmonitoring using a specific G-RNTI to receive a specific service. Here,a DRX on-duration period may be configured exclusively for an SC-PTM fora specific service/specific G-RNTI. In this case, the UEs wake up onlyfor a specific on-duration period and perform PDCCH monitoring for theG-RNTI.

Method of Transmitting One or Multiple PUCCH for ACK/NACK Based or NACKonly Based HARQ-ACK

PUCCH: Physical Uplink Control channel

PUSCH: Physical Uplink Shared Channel

MCCH: Multicast Control Channel

MTCH: Multicast Traffic Channel

RRM: Radio resource management

RLM: Radio link monitoring

SCS: Sub-carrier spacing

RLM: Radio link monitoring

DCI: Downlink Control Information

CAP: Channel Access Procedure

Ucell: Unlicensed cell

PCell: Primary Cell

PSCell: Primary SCG Cell

TBS: Transport Block Size

TDRA: Time Domain Resource Allocation

SLIV: Starting and Length Indicator Value (An indication value for astarting symbol index and the number of symbols in a slot of a PDSCHand/or a PUSCH. It may be configured as a component of an entryconstituting a TDRA field in a PDCCH that schedules a correspondingPDSCH and/or PUSCH.)

BWP: BandWidth Part (It may be composed of continuous resource blocks(RBs) on a frequency axis. It may correspond to one numerology (e.g.,SCS, CP length, slot/mini-slot duration, etc.). In addition, a pluralityof BWPs may be configured in one carrier (the number of BWPs per carriermay also be limited), but the number of activated BWPs may be limited toa part (e.g., one) per carrier.)

CORESET: control resource set (CONtrol REsourse SET) (It means atime-frequency resource region in which a PDCCH can be transmitted, andthe number of CORESETs per BWP may be limited.)

REG: Resource element group

SFI: Slot Format Indicator (An indicator indicating a symbol level DL/ULdirection within a specific slot(s), transmitted through a group commonPDCCH).

COT: Channel occupancy time

SPS: Semi-persistent scheduling

QCL: Quasi-Co-Location (A QCL relationship between two reference signals(RS) may mean that a QCL parameter obtained from one RS such as aDoppler shift, a Doppler spread, an average delay, a delay spread, aspatial Rx parameter, etc. can also be applied to another RS (or antennaport(s) of a corresponding RS). In the NR system, 4 QCL types aredefined as follows. ‘typeA’: {Doppler shift, Doppler spread, averagedelay, delay spread}, ‘typeB’: {Doppler shift, Doppler spread}, ‘typeC’:{Doppler shift, average delay}, ‘typeD’: {Spatial Rx parameter}. Forcertain DL RS antenna port(s), a first DL RS may be configured as areference for QCL type X (X=A, B, C, or D), and a second DL RS may beconfigured as a reference for QCL type Y (Y=A, B, C, or D, but X≠Y).)

TCI: Transmission Configuration Indication (One TCI state includes a QCLrelationship between DM-RS ports of a PDSCH, DM-RS ports of a PDCCH, orCSI-RS port(s) of a CSI-RS resource and one or more DL RSs. For‘Transmission Configuration Indication’ among fields in DCI thatschedules a PDSCH, a TCI state index corresponding to each code pointconstituting the field is activated by a MAC control element (CE), and aTCI state configuration for each TCI state index is configured throughRRC signaling. In the Rel-16 NR system, a corresponding TCI state isconfigured between DL RSs, but a configuration between a DL RS and a ULRS or between a UL RS and a UL RS may be allowed in a future release.Examples of a UL RS include an SRS, a PUSCH DM-RS, and a PUCCH DM-RS.)

SRI: SRS resource indicator (It indicates one of SRS resource indexvalues configured in ‘SRS resource indicator’ among fields in DCIscheduling a PUSCH. When transmitting a PUSCH, a UE may transmit thePUSCH using the same spatial domain transmission filter used fortransmission and reception of a reference signal associated with thecorresponding SRS resource. Here, a reference RS is configured by RRCsignaling through an SRS spatial relation information parameter(SRS-SpatialRelation Info) for each SRS resource, and an SS/PBCH block,a CSI-RS, or an SRS may be configured as the reference RS.)

TRP: Transmission and Reception Point

PLMN ID: Public Land Mobile Network identifier

RACH: Random Access Channel

RAR: Random Access Response

Msg3: This is a message transmitted through an uplink shared channel(UL-SCH) including a C-RNTI MAC CE or a common control channel (CCCH)service data unit (SDU), provided from a higher layer, and associatedwith a UE Contention Resolution Identity as part of a random accessprocedure.

Special Cell: In case of a dual connectivity operation, the term specialcell refers to the PCell of a master cell group (MCG) or the PSCell of asecondary cell group (SCG) depending on whether a MAC entity is relatedto the MCG or the SCG, respectively. Otherwise, the term Special Cellrefers to the PCell. The Special Cell supports PUCCH transmission andcontention-based random access and is always active.

Serving Cell: It includes the PCell, the PSCell, and the secondary cell(SCell).

CG: Configured Grant

Type 1 CG or Type 2 CG: Type 1 configured grant or Type 2 configuredgrant

Fall-back DCI: It indicates a DCI format that can be used for afall-back operation, and for example, corresponds to DCI formats 0_0 and1_0.

non-fall-back DCI: It indicates a DCI format other than the fall-backDCI, for example, corresponds to DCI formats 0_1 and 1_1.

SS: search space

FDRA: frequency domain resource allocation

TDRA: time domain resource allocation

LP, HP: Low(er) priority, High(er) priority

A/N for cell A: A/N (acknowledgement/negative acknowledgment)information for data (e.g., PDSCH) received in cell A

UL CI: Uplink cancelation indication

CFR: Common frequency resource for multicast and broadcast service(MBS). One DL CFR provides group common PDCCH and group common PDSCHtransmission resources for MBS transmission and reception. One UL CFRprovides HARQ-ACK PUCCH resources for group common PDSCH reception. OneCFR is one MBS specific BWP or one UE specific BWP. Alternatively, oneor a plurality of CFRs may be configured in one UE specific BWP. One CFRis associated with one UE specific BWP.

TMGI: Temporary Mobile Group Identity. As an MBS service identifier, itindicates a specific service.

G-RNTI: Group Radio Network Temporary Identifier.

It indicates a UE group identifier that receives an MBS.

The above contents (3GPP system, frame structure, NR system, etc.) canbe applied in combination with methods proposed in the presentdisclosure to be described later, or it may be supplemented to clarifythe technical characteristics of the methods proposed in the presentdisclosure. In this disclosure, ‘/’ means ‘and’, ‘or’, or ‘and/or’depending on the context.

In the prior art, a base station may configure a UE-specific SPSconfiguration for a specific UE and allocate a repeated downlink SPStransmission resource according to a configured period. Here, DCI of aUE-specific PDCCH may indicate activation (SPS activation) of a specificSPS configuration index, and accordingly, the corresponding UE canrepeatedly receive an SPS transmission resource according to aconfigured period. This SPS transmission resource is used for initialHARQ (hybrid automatic repeat request) transmission, and a base stationmay allocate a retransmission resource of a specific SPS configurationindex through DCI of a UE-specific PDCCH. For example, when a UE reportsa HARQ NACK for an SPS transmission resource, a base station canallocate a retransmission resource to DCI so that a UE can receivedownlink retransmission. In addition, DCI of a UE-specific PDCCH mayindicate deactivation (SPS release or SPS deactivation) of a specificSPS configuration index, and a UE receiving this does not receive theindicated SPS transmission resource. Here, a cyclic redundancy check(CRC) of DCI for activation/retransmission/deactivation of the SPS isscrambled with Configured Scheduling-RNTI (CS-RNTI).

Rel-17 NR intends to introduce a DL broadcast or DL multicasttransmission method to support a Multicast Broadcast Service (MBS)service similar to LTE MBMS. A base station provides apoint-to-multipoint (PTM) transmission method and/or a point-to-point(PTP) transmission method for DL broadcast or DL multicast transmission.

In a PTM transmission method for an MBS, a base station transmits agroup common PDCCH and a group common PDSCH to a plurality of UEs, and aplurality of UEs simultaneously receive the same group common PDCCH andgroup common PDSCH transmission to decode the same MBS data.

On the other hand, in a PTP transmission scheme for an MBS, a basestation transmits a UE-specific PDCCH and a UE-specific PDSCH to aspecific UE, and only the corresponding UE receives the UE-specificPDCCH and the UE-specific PDSCH. Here, when there are a plurality of UEsreceiving the same MBS service, a base station separately transmits thesame MBS data to individual UEs through different UE-specific PDCCHs andUE-specific PDSCHs. That is, the same MBS data is provided to aplurality of UE, but different channels (i.e., PDCCH, PDCCH) are usedfor each UE.

As described above, in a PTM transmission method, a base stationtransmits a plurality of group common PDSCHs to a plurality of UEs.Here, a base station can receive UE's HARQ-ACKs for a group common PDSCHthrough respective UE-dedicated PUCCH resources from a plurality of UEs.In addition, a UE may receive group common SPS transmission (i.e.,static scheduling transmission) and group common dynamic schedulingtransmission (dynamically scheduled transmission). In addition, it isalso possible to receive group common SPS transmission and UE-onlystatic/dynamic scheduling transmission. In this case, a situation mayoccur in which a UE transmits HARQ-ACKs for these transmissions togetherin the same slot or sub-slot. For example, PUCCH resource(s) for groupcommon/dedicated SPS and PUCCH resource(s) for group common/dedicateddynamic scheduling transmission may be allocated to the same slot or thesame sub-slot. In this case, HARQ-ACK transmissions for two or moretransmissions may be multiplexed and transmitted on one PUCCH, or someHARQ-ACKs may be dropped (not sent), bundled, or delayed. Therefore, aproblem occurs in that a base station cannot correctly interpretHARQ-ACK information.

Therefore, in the present disclosure, when a plurality of HARQ-ACKs aretransmitted on a PUCCH of the same slot (or sub-slot), a method oftransmitting a plurality of HARQ-ACKs, such as multiplexing, dropping,bundling, or delaying a plurality of (or some) HARQ-ACKs, is proposed.

Hereinafter, in the present disclosure, a DCI format (or PDCCH) forscheduling PDSCH reception carrying an MBS service (i.e., MBS TB) may bereferred to as an MBS DCI format (or PDCCH) or a multicast DCI format(or PDCCH). For example, a DCI format (or PDCCH) with a CRC scrambled bya group-RNTI (G-RNTI) or a group-configured scheduling-RNTI (G-CS-RNTI)may be referred to as an MBS DCI format (or PDCCH) or a multicast DCIformat (or PDCCH). Here, unless otherwise stated in the presentdisclosure, an MBS DCI format (or PDCCH) or a multicast DCI format (orPDCCH) may include both a group common DCI format (or PDCCH) accordingto a PTM method for an MBS and a UE-specific DCI format (or PDCCH)according to a PTP method for an MBS.

In addition, unless otherwise stated in the present disclosure (e.g.,distinction between a PDSCH by dynamic scheduling and a PDSCH by SPS), aPDSCH (also, a PDSCH scheduled by a UE specific DCI format (or PDCCH) ofa PTP method) scheduled by an MBS DCI format (or PDCCH) or a multicastDCI format (or PDCCH) and a group common SPS PDSCH may be collectivelyreferred to as an MBS PDSCH or a multicast PDSCH. In other words, unlessotherwise stated in the present disclosure, an MBS PDSCH or a multicastPDSCH may include both a group common PDSCH according to a PTM schemefor an MBS and a UE specific PDSCH according to a PTP scheme for an MBS.

In addition, HARQ-ACK information associated with a multicast (or MBS)DCI format (or PDCCH) or a multicast PDSCH may be referred to as MBSHARQ-ACK information or multicast HARQ-ACK information. Unless otherwisestated in this disclosure, such MBS HARQ-ACK information or multicastHARQ-ACK information may be transmitted through a UE specificPUCCH/PUSCH according to a PTP/PTM scheme and may be transmitted througha group common PUCCH/PUSCH according to a PTM scheme.

In addition, unless otherwise stated in the present disclosure (e.g.,distinction between a PDSCH by dynamic scheduling and a PDSCH by SPS), aPDSCH scheduled by a unicast DCI format (or PDCCH) and a UE-specific SPSPDSCH may be collectively referred to as a unicast/UE-specific PDSCH.

In addition, in the present disclosure, when a transport block (TB) foran MBS PDSCH or a multicast PDSCH is successfully decoded, a UE maytransmit an ACK as HARQ-ACK information. On the other hand, if a TB foran MBS PDSCH or a multicast PDSCH is not successfully decoded, a UE maytransmit a NACK as HARQ-ACK information. This HARQ-ACK transmissionmethod is referred to as an ACK/NACK based HARQ-ACK method (mode).

On the other hand, when a TB for an MBS PDSCH or a multicast PDSCH issuccessfully decoded, a UE may not transmit HARQ-ACK information (i.e.,ACK) through a PUCCH (or PUSCH). On the other hand, if a TB for an MBSPDSCH or a multicast PDSCH is not successfully decoded, a UE maytransmit a NACK as HARQ-ACK information. This HARQ-ACK transmissionmethod is referred to as an ACK/NACK based HARQ-ACK method (mode). Inother words, when a NACK only based HARQ-ACK method (mode) isconfigured, a UE may not perform PUCCH (or PUSCH) transmission in caseof an ACK, and may perform PUCCH (or PUSCH) transmission only in case ofa NACK.

In addition, in the present disclosure, a sub-slot, a mini-slot, and asymbol slot all represent time units smaller than one slot, and unlessclearly distinguished and described for each in the present disclosure,all may be interpreted in the same meaning. Also, all of the above termsmay be regarded/interpreted as one or more symbols in a slot.

The present disclosure supports the following schemes.

When multiple unicast HACK-ACK(s) of high priority (HP) for unicastPDSCH(s), X multicast HARQ-ACK(s) of HP for multicast PDSCH(s), Ymulticast HARQ-ACK(s) of LP for multicast

PDSCH(s) overlap in the same slot, a UE may transmit PUCCH(s) asfollows.

1) Option 1: A UE supporting two time division multiplexed PUCCHs maytransmit two PUCCHs in the slot (e.g., when PUCCH configuration formulticast (e.g., RRC parameter ‘PUCCH-Config’) and PUCCH configurationfor unicast (e.g., PUCCH-Config) are separately configured).

Option 1-1: A UE may transmit one PUCCH (some multicast HARQ-ACKs may ormay not be dropped) carrying a separate HARQ-ACK codebook formultiplexed multicast HARQ-ACK(s) and one PUCCH carrying a separateHARQ-ACK codebook for unicast HARQ-ACK(s).

Option 1-2: A UE may transmit one PUCCH for multiplexed multicastHARQ-ACK(s) (some multicast HARQ-ACKs may or may not be dropped), andmay transmit one PUCCH for multiplexed multicast HARQ-ACK(s) and unicastHARQ-ACK(s).

2) Option 2: A UE that does not support two PUCCHs (e.g., when PUCCHconfiguration (e.g., PUCCH-Config) for multicast is not separatelyconfigured) may transmit only one PUCCH and drop the other PUCCH.

3) Option 3: According to a UE capability or a maximum PUCCH payloadsize, a UE may drop all or part of multicast HARQ-ACK(s) with LP.

4) Option 4: A UE may defer all or part of multicast HARQ-ACK(s) to thenext PUCCH transmission (e.g., depending on whether PUCCH configurationfor multicast (e.g., PUCCH-Config) and PUCCH configuration for unicast(e.g., PUCCH-Config) are separately configured), and transmit theremaining unicast/multicast HARQ-ACK(s) on a PUCCH in the current slot.

Option 4-1: Z (Z is a natural number) multicast HARQ-ACK (s) may bedeferred to the next PUCCH transmission allocated for a unicast or othermulticast PDSCH. Deferred multicast HARQ-ACK(s) may be multiplexed withnext unicast HARQ-ACK(s) and/or other multicast HARQ-ACK(s).

Option 4-2: Z (Z is a natural number) multicast HARQ-ACK(s) may bedeferred to the next PUCCH transmission allocated for other multicastPDSCH(s) (not unicast PDSCH) (e.g., when PUCCH configuration (e.g.,PUCCH-Config) for multicast is separately configured).

5) Option 5: A UE may bundle multicast HARQ-ACK(s) and unicastHARQ-ACK(s).

Option 5-1: Z (Z is a natural number) multicast HARQ-ACK(s) may bebundled with K (K<Z) HARQ-ACK bit(s).

Option 5-2: Z (Z is a natural number) multicast HARQ-ACK(s) and unicastHARQ-ACK(s) may be bundled with K (K<Z) HARQ-ACK bit(s) (e.g., whenPUCCH configuration (e.g., PUCCH-Config) for multicast is not separatelyconfigured).

Meanwhile, i) in the case of two PUCCH transmissions of multicastHARQ-ACK(s) and unicast HARQ-ACK(s), respectively or ii) in the case ofmultiplexing multicast HARQ-ACK(s) and unicast HARQ-ACK(s) on one PUCCH,if a PUCCH of N symbol slots for unicast HARQ-ACK(s) is determined, aPUCCH of N symbol slots should also be determined for multicastHARQ-ACK(s). If a PUCCH of N symbol slots cannot be determined formulticast HARQ-ACK(s) (e.g., when a PUCCH with N symbol slot(s) is notconfigured in a PUCCH configuration (e.g., PUCCH-Config) for multicast),multicast HARQ-ACK(s) may be dropped or deferred. Alternatively, if aPUCCH with N symbol slot(s) cannot be determined for multicastHARQ-ACK(s) based on a PUCCH configuration (e.g., PUCCH-Config) formulticast, a PUCCH with N symbol slot(s) for multicast HARQ-ACK(s) maybe determined based on a PUCCH configuration (e.g., PUCCH-Config) forunicast.

Meanwhile, when a UE triggers a random access procedure (RACH), the UEmonitors a group common PDCCH and receives a group common PDSCH asfollows:

1) After triggering a RACH, a UE monitors a group common PDCCH.

When a RACH is triggered, a UE suspends group common PDCCH monitoringand group common PDSCH reception.

A UE resumes group common PDCCH reception after one of MSG1, MSG2, MSG3,and MSG4 of step 4 RACH or one of MSGA and MSGB of step 2 RACH.

n case of step 4 RACH, a UE prioritizes MSG1, MSG2, MSG3, and MSG4 overgroup common PDCCH/PDSCH reception and HARQ-ACKs for a group commonPDSCH.

In case of step 2 RACH, a UE prioritizes MSGA and MSGB over group commonPDCCH/PDSCH reception and HARQ-ACKs for a group common PDSCH.

2) A UE may transmit an MBS HARQ-ACK on a PUCCH immediately afterMSG2/MSGB reception (in case of contention-free RACH (CF-RACH)) or firstMSG3 transmission (contention-based RACH (CB-RACH)).

A UE cannot transmit an MBS HARQ-ACK without UL synchronization.

MSG3 is not multiplexed with a PUCCH A/N.

A UE cannot perform a HARQ-ACK before MSG3 (or MSG2/MSGB), but canperform a HARQ-ACK after MSG3 (or MSG2/MSGB).

Hereinafter, a HARQ-ACK transmission method proposed in the presentdisclosure will be described.

In the present disclosure, an MBS HARQ-ACK (or multicast HARQ-ACK) meansa HARQ-ACK for PTM PDSCH-based MBS service downlink transmission and/ora HARQ-ACK for PTP PDSCH-based MBS service downlink transmission.

FIG. 9 illustrates a HARQ-ACK transmission and reception procedureaccording to an embodiment of the present disclosure.

FIG. 9 (a) illustrates a signaling procedure between UE1 and a basestation (gNB) (beam/TRP 1), and FIG. 9(b) illustrates a signalingprocedure between UE2 and a base station (gNB) (beam/TRP 2). Inaddition, FIG. 9(a) illustrates a case without PDSCH retransmission, andFIG. 9(b) illustrates a case with PDSCH retransmission. In FIG. 9 , forconvenience of description, two procedures are illustrated together, butthe present disclosure is not limited thereto. That is, UE1 and UE2 arenot limited to accessing the same base station (through differentbeams/TRPs), and are not limited to performing the two procedurestogether. In other words, although FIGS. 9(a) and 9(b) are separateprocedures, they are shown together for convenience of explanation, andcommon descriptions are described for common steps.

1. Although not shown in FIG. 9 , (before the procedure of FIG. 9 ), aUE may enter an RRC connected mode (RRC_CONNECTED mode) and may transmita messages/information that indicates one or more MBS services ofinterest to a base station.

A. The message/information may be transmitted through any one of uplinkcontrol information (UCI), a MAC control element (CE), and an RRCmessage.

B. An interested MBS service in the message/information may mean eitherTMGI or G-RNTI included in a DL message received from a base station.

For example, the DL message may be a service availability messageincluding TMGI#1, TMGI#3, TMGI#5 and TMGI#10. If a UE is interested inTMGI#5, the UE may indicate an order of TMGI#5 in themessage/information. That is, the UE may report ‘3’ to the base station.

As another example, the DL message may be a service availability messageincluding G-RNTI#1, G-RNTI#3, G-RNTI#5 and G-RNTI#10. If a UE isinterested in G-RNTI#10, the UE may indicate an order of G-RNTI#10 inthe message/information. That is, the UE may report ‘4’ to the basestation.

2. Referring to FIG. 9 , upon receiving the message/information, a basestation may transmit at least one of i) a common frequency resource(CFR) configuration, ii) one or more group common PDSCH configurationsincluding TCI states for one or more G-RNTI value(s), iii) a searchspace (SS) configuration including TCI states for one or more G-RNTIvalue(s) to the UE through an RRC message (S901 a, S901 b).

Although one RRC message is illustrated in FIG. 9 , it is not limitedthereto, and the configurations i) to iii) may be provided to a UEthrough different (or partially identical) RRC messages.

Upon receiving an RRC message from a base station, a UE may configureone or more group common PDSCH (e.g., group common SPS PDSCH)configurations according to the RRC message.

A. An RRC message may be a group common message transmitted on a PTMmulticast control channel (MCCH) or a UE-specific message transmitted ona UE-specific dedicated control channel (DCCH).

B. A UE may be configured with at least a G-RNTI value for each MBS CFRor each serving cell. Alternatively, in addition to this, a GC-CS-RNTI(group common-configured scheduling-RNTI) may also be configured, andmay be used for activating, retransmitting, or releasing one or moregroup common SPS configurations.

if a UE has not configured with a GC-CS-RNTI for a CFR or a servingcell, when a CS-RNTI has been configured for the CFR or the servingcell, the UE may use the CS-RNTI to activate, retransmit or release oneor more group common SPS configurations.

A base station may associate a list of TMGIs or a list of G-RNTIs withone GC-CS-RNTI. In this case, a base station may provide a UE with alist of TMGIs or a list of G-RNTIs associated with the GC-CS-RNTI value.

C. Each PDSCH configuration (e.g., RRC parameter PDSCH-config) mayinclude at least information elements (IE) for multicast and/orbroadcast as shown in Table 6 below.

Table 6 illustrates the PDSCH-Config IE used to configure PDSCHparameters.

TABLE 6 PDSCH-Config ::= SEQUENCE {  dataScramblingIdentityPDSCH INTEGER(0..1023) OPTIONAL, -- Need S  dmrs-DownlinkForPDSCH-MappingTypeASetupRelease { DMRS-DownlinkConfig }  OPTIONAL, -- Need M dmrs-DownlinkForPDSCH-MappingTypeB SetupRelease { DMRS-DownlinkConfig } OPTIONAL, -- Need M  tci-StatesToAddModList SEQUENCE(SIZE(1..maxNrofTCI-States)) OF TCI-State  OPTIONAL, -- Need N tci-StatesToReleaseList SEQUENCE (SIZE(1..maxNrofTCI-States)) OF TCI- StateId OPTIONAL, -- Need N  vrb-ToPRB-Interleaver ENUMERATED {n2, n4}OPTIONAL, -- Need S  resourceAllocation ENUMERATED {resourceAllocationType0,  resourceAllocationType1, dynamicswitch}, pdsch-TimeDomainAllocationList SetupRelease { PDSCH- TimeDomainResourceAllocationList } OPTIONAL, -- Need M pdsch-AggregationFactor ENUMERATED { n2, n4, n8 } OPTIONAL, -- Need S rateMatchPatternToAddModList SEQUENCE (SIZE (1..maxNrofRateMatchPatterns)) OF RateMatchPattern OPTIONAL, -- Need N rateMatchPatternToReleaseList SEQUENCE (SIZE (1..maxNrofRateMatchPatterns)) OF RateMatchPatternId OPTIONAL, -- NeedN  rateMatchPatternGroup1 RateMatchPatternGroup OPTIONAL, -- Need R rateMatchPatternGroup2 RateMatchPatternGroup OPTIONAL, -- Need R rbg-Size ENUMERATED {config1, config2},  mcs-Table ENUMERATED {qam256,qam64LowSE} OPTIONAL, -- Need S  maxNrofCodeWordsScheduledByDCIENUMERATED {n1, n2}  ... }

Table 7 illustrates a description of the fields of the PDSCH-config ofFIG. 6 above.

TABLE 7 PDSCH-Config field descriptions dataScramblingIdentityPDSCH,dataScramblingIdentityPDSCH2 Identifier(s) used to initialize datascrambling (c_init) for PDSCH. The dataScramblingIdentityPDSCH2 isconfigured if coresetPoolIndex is configured with 1 for at least oneCORESET in the same BWP. dmrs-DownlinkForPDSCH-MappingTypeA,dmrs-DownlinkForPDSCH- MappingTypeA-DCI-1-2 DMRS configuration for PDSCHtransmissions using PDSCH mapping type A (chosen dynamically via PDSCH-TimeDomainResourceAllocation). Only the fields dmrs-Type,dmrs-AdditionalPosition and maxLength may be set differently for mappingtype A and B. The field dmrs-DownlinkForPDSCH- MappingTypeA applies toDCI format 1_1 and the field dmrs- DownlinkForPDSCH-MappingTypeA-DCI-1-2applies to DCI format 1_2. dmrs-DownlinkForPDSCH-MappingTypeB,dmrs-DownlinkForPDSCH- MappingTypeB-DCI-1-2 DMRS configuration for PDSCHtransmissions using PDSCH mapping type B (chosen dynamically via PDSCH-TimeDomainResourceAllocation). Only the fields dmrs-Type,dmrs-AdditionalPosition and maxLength may be set differently for mappingtype A and B. The field dmrs-DownlinkForPDSCH- MappingTypeB applies toDCI format 1_1 and the field dmrs- DownlinkForPDSCH-MappingTypeB-DCI-1-2applies to DCI format 1_2. maxNrofCodewordsScheduledByDCI Maximum numberof code words that a single DCI may schedule. This changes the number ofMCS/RV/NDI bits in the DCI message from 1 to 2. mcs-Table,mcs-TableDCI-1-2 Indicates which MCS table the UE shall use for PDSCH.If the field is absent the UE applies the value 64QAM. The fieldmcs-Table applies to DCI format 1_0 and DCI format 1_1, and the fieldmcs-TableDCI-1-2 applies to DCI format 1_2. pdsch-AggregationFactorNumber of repetitions for data. When the field is absent the UE appliesthe value 1. pdsch-TimeDomainAllocationList, pdsch-TimeDomainAllocationListDCI-1-2 List of time-domain configurations fortiming of DL assignment to DL data. The fieldpdsch-TimeDomainAllocationList (with or without suffix) applies to DCIformat 1_0 and DCI format 1_1, and if the fieldpdsch-TimeDomainAllocationListDCI-1-2 is not configured, to DCI format1_2. If the field pdsch- TimeDomainAllocationListDCI-1-2 is configured,it applies to DCI format 1_2. The network does not configure the pdsch-TimeDomainAllocationList-r16 simultaneously with the pdsch-TimeDomainAllocationList (without suffix) in the same PDSCH- Config.rateMatchPatternGroup1, rateMatchPatternGroup1DCI-1-2 The IDs of a firstgroup of RateMatchPatterns defined inPDSCH-Config−>rateMatchPatternToAddModList (BWP level) or inServingCellConfig −>rateMatchPatternToAddModList (cell level). Thesepatterns can be activated dynamically by DCI. The fieldrateMatchPatternGroup1 applies to DCI format 1_1, and the fieldrateMatchPatternGroup1DCI-1-2 applies to DCI format 1_2.rateMatchPatternGroup2, rateMatchPatternGroup2DCI-1-2 The IDs of asecond group of RateMatchPatterns defined inPDSCH-Config−>rateMatchPatternToAddModList (BWP level) or inServingCellConfig −>rateMatchPatternToAddModList (cell level). Thesepatterns can be activated dynamically by DCI. The fieldrateMatchPatternGroup2 applies to DCI format 1_1, and the fieldrateMatchPatternGroup2DCI-1-2 applies to DCI format 1_2.rateMatchPatternToAddModList Resources patterns which the UE should ratematch PDSCH around. The UE rate matches around the union of allresources indicated in the rate match patterns. rbg-Size Selectionbetween config 1 and config 2 for RBG size for PDSCH. The UE ignoresthis field if resourceAllocation is set to resourceAllocationType1.resourceAllocation, resourceAllocationDCI-1-2 Configuration of resourceallocation type 0 and resource allocation type 1 for non-fallback DCI.The field resourceAllocation applies to DCI format 1_1, and the fieldresourceAllocationDCI-1-2 applies to DCI format 1_2.resourceAllocationType1GranularityDCI-1-2 Configure the schedulinggranularity applicable for both the starting point and length indicationfor resource allocation type 1 in DCI format 1_2. If this field isabsent, the granularity is 1 PRB. tci-StatesToAddModList A list ofTransmission Configuration Indicator (TCI) states indicating atransmission configuration which includes QCL- relationships between theDL RSs in one RS set and the PDSCH DMRS ports. vrb-ToPRB-Interleaver,vrb-ToPRB-InterleaverDCI-1-2 Interleaving unit configurable between 2and 4 PRBs. When the field is absent, the UE performs non-interleavedVRB-to-PRB mapping.

3. Although not shown in FIG. 9 , for HARQ-ACK transmission of whetherreception of MBS transmission is successful, a base station maypreconfigure a PUCCH configuration (e.g., PUCCH-config) to a UE througha higher layer message (e.g., RRC message). Here, when a UE receives anMBS service, a base station may preconfigure a PUCCH configuration forseparate multicast for an MBS HARQ-ACK to a UE in addition to a PUCCHconfiguration for unicast provided in the prior art.

A. In addition, a base station may separately provide a PUCCHconfiguration for multicast (e.g. PUCCH-config) and a PUCCHconfiguration for unicast (e.g. PUCCH-config) to a UE through a higherlayer message (e.g., RRC message).

Here, for a PUCCH resource ID in a PUCCH configuration (e.g.,PUCCH-config) for multicast in a higher layer message (e.g., RRCmessage), ‘NACK only based HARQ-ACK’ may be configured. Here, anACK/NACK-based HARQ-ACK reporting (mode) means a method (mode) in whicha UE transmits an ACK or a NACK to a base station according to whetherdecoding of a TB is successful, and a NACK only based HARQ-ACK reporting(mode) means a method (mode) in which HARQ-ACK information includingonly ACK values is not transmitted through a PUCCH. An ACK/NACK basedHARQ-ACK reporting (mode) may be referred to as a first HARQ-ACKreporting (mode), and a NACK only based HARQ-ACK reporting (mode) may bereferred to as a second HARQ-ACK reporting (mode).

If a NACK only based HARQ-ACK is not configured for a PUCCH resource ID,a UE may consider that an ACK/NACK based HARQ-ACK is configured for thePUCCH resource ID.

A PUCCH resource indicator (PRI) value of DCI may indicate (select) aPUCCH resource ID of a PUCCH configuration (e.g., PUCCH-config) formulticast, and may implicitly indicate a NACK only based HARQ-ACK or anACK/NACK based HARQ-ACK for the corresponding PUCCH resource ID.

Here, a NACK only based HARQ-ACK may not be configured by a PUCCHconfiguration for unicast (e.g., PUCCH-config).

If both a NACK-only based HARQ-ACK and an ACK/NACK based HARQ-ACK areconfiguration for a group common SPS configuration, RRC signaling, DCIor MAC CE can enable/disable only one of a NACK-only based HARQ-ACK andan ACK/NACK based HARQ-ACK for the group common SPS configuration.

In addition, When both a NACK-only based HARQ-ACK and an ACK/NACK basedHARQ-ACK are configured for a group common PDSCH dynamically scheduledby DCI with a CRC scrambled by one of a C-RNTI, a CS-RNTI, a G-RNTI anda G-CS-RNTI, RRC signaling or DCI (or MAC CE) can enable/disable onlyone of a NACK-only based HARQ-ACK and an ACK/NACK based HARQ-ACK for agroup common PDSCH (e.g., for one of C-RNTI, CS-RNTI, G-RNTI andG-CS-RNTI). In other words, one method (mode) of a NACK-only basedHARQ-ACK and an ACK/NACK based HARQ-ACK for one of a C-RNTI, a CS-RNTI,a G-RNTI and a G-CS-RNTI may be configured by RRC signaling or DCI (orMAC CE). In this case, when a UE receives DCI with a CRC scrambled byone of a C-RNTI, a CS-RNTI, a G-RNTI and a G-CS-RNTI, one of a NACK-onlybased HARQ-ACK and an ACK/NACK based HARQ-ACK configured (active) for acorresponding C-RNTI, a CS-RNTI, a G-RNTI and a G-CS-RNTI may beconfigured/determined as a HARQ-ACK reporting method for a multicast orunicast PDSCH scheduled by the corresponding DCI.

B. A PUCCH configuration (e.g., PUCCH-config) for multicast may beconfigured for each CFR or for each active UL BWP of a UE related to aCFR.

C. Group common PUCCH resource(s) for a NACK only based HARQ-ACK may beconfigured within a UL CFR configured within an active UL BWP of a UE.

Here, group common PUCCH resource(s) may be configured only by a PUCCHconfiguration for multicast (e.g., PUCCH-config).

In addition, UE specific PUCCH resource(s) may be configured on anactive BWP of a UE.

D. A NACK only based HARQ-ACK may be transmitted on group common PUCCHresource(s).

E. Different group common PUCCH resource(s) may be related to differentDL RSs (e.g., in terms of symbols/slots and/or PRBs and/or sequences forPUCCHs).

F. A NACK only based HARQ-ACK may be configured for a PUCCH resource IDin a PUCCH configuration (e.g., PUCCH-config) for multicast.

If a NACK only based HARQ-ACK is not configured for a PUCCH resource ID,a UE may consider that an ACK/NACK based HARQ-ACK is configured for thePUCCH resource ID.

A PRI value of DCI may indicate (select) a PUCCH resource ID of a PUCCHconfiguration (e.g., PUCCH-config) for multicast, and may implicitlyindicate a NACK only based HARQ-ACK or an ACK/NACK based HARQ-ACK for acorresponding PUCCH resource ID.

Here, a NACK only based HARQ-ACK may not be configured by a PUCCHconfiguration for unicast (e.g., PUCCH-config).

G. Alternatively, a NACK only based HARQ-ACK may be configured only in aPUCCH configuration (e.g., PUCCH-config) for multicast.

A NACK only based HARQ-ACK cannot be configured with a PUCCHconfiguration (e.g., PUCCH-config) for unicast.

One of the following options may be used to configure a NACK only basedHARQ-ACK within a PUCCH configuration (e.g., PUCCH-config) formulticast.

i) Option 1: A NACK only based HARQ-ACK and an ACK/NACK based HARQ-ACKmay be configured for different PUCCH resource set IDs.

ii) Option 2: A NACK only based HARQ-ACK and an ACK/NACK based HARQ-ACKmay be configured for different PUCCH resource IDs.

When a NACK only based HARQ-ACK is not configured for a PUCCH resourceset ID and/or a PUCCH resource ID, a UE may consider that an ACK/NACKbased HARQ-ACK is configured for the corresponding PUCCH resource set IDand/or the corresponding PUCCH resource ID.

4. Referring to FIG. 9 again, when a search space (SS) for a configuredCFR is configured, a UE monitors a PDCCH on the SS configured in the CFRconfigured to receive DCI with a CRC scrambled with a G-RNTI or aG-CS-RNTI (S902 a, S902 b).

5. If a data unit is available in a Multicast Traffic Channel (MTCH) ofan MBS radio bearer (MRB) for an MBS service, according to aservice-to-resource mapping, a base station constructs and transmits atransport block (TB) including a data unit for an SPS PDSCH occasion, i)associated with an MTCH of an MRB for an MBS service, ii) associatedwith a TMGI of an MBS service, iii) associated with a short ID of an MBSservice, or iv) associated with a G-RNTI mapped to an MBS service.

In the case of group common dynamic scheduling of a

TB, a base station transmits DCI to a UE on a PDCCH (S903 a, S903 b).

Here, a CRC of the DCI may be scrambled by a G-RNTI, a G-CS-RNTI or aCS-RNTI. Also, a PDCCH may be a group common PDCCH or a UE specificPDCCH.

In FIG. 9 , a case in which a group common DCI with a CRC scrambled withG-RNTI#1 is transmitted, and repetition=3 is exemplified.

The DCI may include the following information (fields).

Identifier for DCI format: This information (field) may indicate eitheran MBS-specific DCI format or one of an existing DCI format for an MBS.

Carrier indicator: This information (field) indicates a (serving or MBSspecific) cell of a CFR through which a group common PDCCH/PDSCH istransmitted or a serving cell of an active BWP of a UE associated withthe CFR.

Bandwidth part indicator: This information (field) indicates a BWP IDassigned to a CFR through which a group common PDCCH/PDSCH istransmitted or a BWP ID of an active BWP of a UE associated with theCFR.

In addition, the DCI may include information on a frequency domainresource assignment, a time domain resource assignment, a VRB-to-PRBmapping, and a PRB bundling size indicator, a rate matching indicator, aZP CSI-RS trigger, a modulation and coding scheme, a new data indicator(NDI), a redundancy version, a HARQ process number, a downlinkassignment index, a transmit power control (TPC) command for a scheduledPUCCH, a PUCCH resource Indicator (PRI), a PDSCH-to-HARQ_feedback timingindicator (PDSCH-to-HARQ_feedback timing indicator), antenna port(s), atransmission configuration indication (TCI), an SRS request, a DMRSsequence initialization, and a priority indicator.

In the case of group common dynamic scheduling, a base station mayprovide a UE with one or more of the following service-to-resourcemappings for an MBS service identified by a TMGI or a G-RNTI or aGC-CS-RNTI i) by a group common or UE-specific RRC message or ii) by agroup common or UE-specific MAC CE. Data of an MBS service can becarried over an MBS radio bearer (MRB) of an MTCH associated with an MBSservice, which is a multicast traffic logical channel. An RRC messagemay be a group common message transmitted through a PTM MulticastControl Channel (MCCH) or a UE-specific message transmitted through aUE-specific Dedicated Control Channel (DCCH). DCI scheduling a

PDSCH carrying MBS service data may also indicate one or more of a shortID, an MTCH ID, an MRB ID, a G-RNTI value, and a TMGI value for an MBSservice.

6. If a UE receives DCI with a CRC scrambled by a G-RNTI of interest inreceiving, based on i) a mapping between MBS services and a HARQ processnumber (HPN) indicated in DCI and/or ii) (if available) a mappingbetween MBS services and an indicated short ID(s) in DCI, a UE maydetermine an MBS service related to one or more of short ID, MTCH ID,MRB ID, G-RNTI value, and TMGI value for each PDSCH occasion.

A base station may transmit a PDSCH carrying corresponding MBS servicedata to a UE (S904 a, S904 b) (In FIG. 9 , the case where MBS servicedata mapped with G-RNTI#1 is transmitted is exemplified), and if a UE isinterested in the determined MBS service(s), the UE can receive PDSCHtransmission scheduled by DCI (S905 a, S905 b).

On the other hand, different from the example of FIG. 9 , if a UE is notinterested in the determined MBS service(s), the UE may not receivePDSCH transmission scheduled by DCI.

Then, according to the decoding state of PDSCH transmission, a UEtransmits HARQ feedback to a base station.

7. A UE receiving group common DCI indicating PUCCH resource(s) for anMBS HARQ-ACK may transmit a HARQ-ACK to a base station through a PUCCHafter receiving a PDSCH scheduled by DCI as follows (S906 a).

A. A PUCCH Resource Indicator (PRI) may be indicated as follows by agroup common DCI.

1) Option 1A-1: A list of UE specific PRIs may be included in DCI.

Each PRI in a list may indicate an entry corresponding to a candidatePUCCH resource ID (e.g., pucch-ResourceId) value in a PUCCHconfiguration (e.g. PUCCH-config) for the same PUCCH resource ordifferent PUCCH resource allocation for other UEs of a group receivingthe same DCI. Other PRIs of DCI may indicate different entries in aPUCCH configuration (e.g., PUCCH-config).

A candidate PUCCH resource ID (e.g., pucch-ResourceId) value isconfigured by a higher layer (e.g., RRC), at least in multicast PUCCHconfiguration (e.g., PUCCH-config), different PUCCH resource ID (e.g.,pucch-ResourceId) values may be configured for different UEs of the samegroup.

2) Option 1A-2: group common PRI may be included in DCI.

A single group common PRI may indicate a corresponding entry for acandidate PUCCH resource ID (e.g., pucch-ResourceId) value in a UEspecific PUCCH configuration (e.g., PUCCH-config) for the same ordifferent PUCCH resource allocation for all UEs in a group.

A candidate PUCCH resource ID (e.g., pucch-ResourceId) value isconfigured by a higher layer (e.g., RRC), at least in PUCCHconfiguration for multicast (e.g., PUCCH-config), different PUCCHresource ID (e.g., pucch-ResourceId) values may be configured fordifferent UEs of the same group.

B. K1 (PDSCH-to-HARQ_feedback timing indicator) may be indicated bygroup common DCI as follows.

1) Option 1B-1: A list of UE specific K1 values may be included in DCI.

Each K1 in a list may indicate the same UL slot or different UL(sub)slots for other UEs in a group.

As an example, different K1 values may be assigned to different UEs. Forexample, K1-UE1, K2-UE2, K3-UE3.

As another example, a K1 value may be shared by multiple UEs (e.g.,K1-UE1/UE2, K2-UE3/UE4).

As another example, one K1 value may be a reference and other K1 valuesmay be assigned based on the reference. For example, a list of {K1_ref,K1_offset (offset from reference)} may be indicated in DCI.

For example, UE1 may use K1_ref, UE2 may use K1_ref+K1_offest1, and UE3may use K1_ref+K1_offest2.

2) Option 1B-2: A group common K1 value may be included in DCI.

single K1 value may indicate a corresponding entry for a candidate DLdata-UL ACK value (e.g., dl-DataToUL-ACK) in a UE specific PUCCHconfiguration (e.g., PUCCH-config) for the same or different PUCCHresource allocation for all UEs of a group receiving DCI.

A candidate DL data-UL ACK value (e.g., dl-DataToUL-ACK) is configuredby a higher layer (e.g., RRC), at least the PUCCH configuration formulticast (e.g., PUCCH-config) can be different for different UEs in thesame group.

C. In addition, when receiving group common DCI with a CRC scrambled bya G-RNTI and/or UE specific DCI with a CRC scrambled by a C-RNTI, when aType-1 HARQ-ACK codebook for a PUCCH-config for multicast and/or aPUCCH-config for unicast is configured, a UE may configure Time DomainResource Allocation (TDRA) to generate a type 1 HARQ-ACK codebook forHARQ-ACK(s) for a group common PDSCH scheduled by group common DCIand/or a UE specific PDSCH scheduled by UE specific DCI.

D. A UE may configure a TDRA as follows.

1) For DCI reception with a CRC scrambled by a G-RNTI, a UE mayconfigure TDRA as follows.

If a DL data-UL ACK value (e.g., dl-DataToUL-ACK) is not configured in aPUCCH configuration (e.g., PUCCH-config) for multicast, a UE may followa DL data-UL ACK value (e.g., dl-DataToUL-ACK) in a PUCCH configuration(e.g., PUCCH-config) for unicast (e.g., for codebook construction ofmulticast received slot/TRP/cell). Here, a UE may configure TDRA basedon a K1 set of unicast.

If a DL data-UL ACK value (e.g., dl-DataToUL-ACK) is configured in aPUCCH configuration (e.g., PUCCH-config) for multicast, a UE may followa DL data-UL ACK value (e.g., dl-DataToUL-ACK) in a PUCCH configuration(e.g., PUCCH-config) for multicast (e.g., for codebook construction ofmulticast received slot/TRP/cell). Here, a UE may configure TDRA basedon a K1 set of multicast.

If a DL data-UL ACK value (e.g., dl-DataToUL-ACK) (e.g., for DCI format1_1/2) is configured in a PUCCH configuration (e.g., PUCCH-config) forunicast or multicast, a UE may follow a DL data-UL ACK value (e.g.,dl-DataToUL-ACK) (e.g., for DCI format 1_1/2) in a PUCCH configuration(e.g., PUCCH-config) for either unicast or multicast (e.g., for codebookconstruction of multicast received slot/TRP/cell). Here, a UE mayconfigure TDRA of DCI format 1_0 by truncation based on K1 configured ofDCI format 1_1/2.

2) For DCI reception with a CRC scrambled by a C-RNTI, a UE mayconfigure TDRA in a conventional manner.

Even for PTP retransmission reception for an MBS TB, a UE may configureTDRA based on C-RNTI DCI.

E. Meanwhile, if only one of a normal uplink (NUL) and a supplementaluplink (SUL) configures a PUCCH configuration (e.g., PUCCH-config) foran MBS, and, if a UE cannot select a PUCCH carrier (i.e., NUL or SUL)configured in a PUCCH configuration (e.g., PUCCH-config) for an MBSbased on a threshold, a UE may operate as follows:

Option 1: A UE may select a PUCCH carrier based on a PUCCH configuration(e.g., PUCCH-config) for unicast to transmit an MBS HARQ-ACK.

Option 2: A UE may ignore a threshold and select a carrier (NUL or SUL)configured in a PUCCH configuration (e.g., PUCCH-config) for an MBS.

F. Meanwhile, if a NACK-only based HARQ-ACK is configured for only oneof NUL and SUL, and if a UE cannot select a PUCCH carrier (i.e., NUL orSUL) configured in a PUCCH configuration for an MBS (e.g., PUCCH-config)based on a threshold, a UE can operate as follows:

Option 1: A NACK-only based HARQ-ACK may be changed to an ACK/NACK basedHARQ-ACK (e.g., may be considered by a UE).

Option 2: A UE may ignore a threshold and select a carrier (NUL or SUL)configured in a PUCCH configuration (e.g., PUCCH-config) for an MBS.

G. On the other hand, when an ACK/NACK based HARQ-ACK is configured anda PUCCH configuration (e.g., PUCCH-config) for multicast is notconfigured, a UE may determine a PUCCH resource for MBS HARQ-ACKtransmission in one or more of the following methods (e.g., acombination of a plurality of methods).

1) Method of allocating a PUCCH resource of a PUCCH configuration (e.g.,PUCCH-config) for unicast corresponding to a PRI and K1 of DCI

Option 1: If only a PUCCH configuration (e.g., PUCCH-config) for unicastis configured, a UE may ignore a PRI of group common DCI and nottransmit an MBS HARQ-ACK.

If a UE receives a PRI of UE specific DCI for PTP PDSCH transmission, aThe UE may transmit a HARQ-ACK for a PTP PDSCH by applying a PUCCHconfiguration for unicast (e.g., PUCCH-config).

Alternatively, even when a UE receives a PRI of UE specific DCI for PTPPDSCH transmission, since it is a HARQ-ACK for multicast, the UE mayignore the corresponding PRI and not transmit a HARQ-ACK for a PTPPDSCH.

Option 2: A UE may transmit an MBS HARQ-ACK by mapping a PRI of DCI to acandidate PUCCH resource ID value (e.g., pucch-ResourceId) of a PUCCHconfiguration (e.g., PUCCH-config) for unicast.

In this case, a UE may transmit an MBS HARQ-ACK using a PUCCH resourcemapped to a candidate PUCCH resource ID value (e.g., pucch-ResourceId)of a PUCCH configuration (e.g., PUCCH-config) indicated by a PRI of DCIas in Option 1′ of 2) below Method 1. For example, when Group common DCIindicates a UE specific PRI as in option 1A-1 above, a UE may transmitan MBS HARQ-ACK using a PUCCH resource corresponding to a PRI indicatedin a PUCCH configuration (e.g., PUCCH-config) for unicast.

2) Method of allocating a PUCCH resource of a PUCCH configuration (e.g.,PUCCH-config) for unicast corresponding to a PRI and K1 of DCI whenmultiple PUCCHs are simultaneously transmitted

Option 1: When a UE receives group common DCI and the DCI includes a PRIand K1 for an MBS, the UE may transmit an MBS HARQ-ACK on a PUCCHresources of a PUCCH configuration (e.g., PUCCH-config) for unicastindicated by a PRI and K1 for the included MBS.

Option 2: When a UE receives UE specific DCI including a PRI/K1 forRel-15/16 and a PRI/K1 for an MBS at the same time, a UE may transmit anMBS HARQ-ACK with a PUCCH resource of a PUCCH configuration (e.g.,PUCCH-config) for unicast indicated by a PRI and K1 for the includedMBS. Meanwhile, in a PUCCH resource according to a PRI/K1 for Rel-15/16,a UE may transmit a HARQ-ACK for a unicast PDSCH according to the priorart.

3) Method of allocating a PUCCH resource of a PUCCH configuration (e.g.,PUCCH-config) for unicast corresponding to a PRI and K1 of DCI whenmultiple PUCCHs are not transmitted simultaneously

Option 1: When group common DCI received by a UE includes a PRI for anMBS, a UE may ignore a PRI for the included MBS and not transmit an MBSHARQ-ACK.

Option 2: When group common DCI received by a UE includes a UE specificMBS PRI/K1, a UE may transmit an MBS HARQ-ACK in a PUCCH resource of aPUCCH configuration (e.g., PUCCH-config) for unicast indicated by theincluded UE specific PRI and K1.

Here, when there is UCI for unicast (e.g., unicast HARQ-ACK or SR orCSI), UCI for unicast and an MBS HARQ-ACK may be multiplexed (mux) andtransmitted.

Furthermore, only a HARQ-ACK for PTP retransmission may be limitedlymultiplexed with unicast UCI and transmitted.

Option 3: When UE specific DCI received by a UE includes only aRel-15/16 PRI/K1, the UE may transmit an MBS HARQ-ACK with a PUCCHresource of a PUCCH configuration (e.g., PUCCH-config) for unicastindicated by the included PRI and K1.

Here, when there is UCI for unicast (e.g., unicast HARQ-ACK or SR orCSI), UCI for unicast and an MBS HARQ-ACK may be multiplexed (mux) andtransmitted.

In addition, only a HARQ-ACK for PTP retransmission may be limitedlymultiplexed with unicast UCI and transmitted.

H. Meanwhile, a base station may provide multicast SPS by configuring UEcommon SPS as follows.

1) In case of a group common SPS PDSCH (not scheduled by DCI butscheduled by RRC), a group common PUCCH resource used for a NACK onlybased HARQ-ACK may be semi-statically configured for one or more groupcommon SPS configurations. (Alternatively, a UE-specific PUCCH resourcefor an ACK/NACK based HARQ-ACK may be configured for one or more groupcommon SPS configurations. Alternatively, a group common PUCCH resourcefor an ACK and a group common PUCCH resource for a NACK may beconfigured separately for one or more group common SPS configurations.)

a) Different SPS configurations may be configured with the same PUCCHresource or different PUCCH resources.

If the same PUCCH resource is allocated for different SPS PDSCHs ofdifferent SPS configurations:

Option 1: One HARQ-ACK bit may indicate an ACK or a NACK for all SPSPDSCHs.

Here, if all SPS PDSCHs are successfully received, a UE may indicate anACK. Alternatively, if one or more SPS PDSCHs are not successfullyreceived, a UE may indicate a NACK.

Option 2: Different HARQ-ACK bits may indicate an ACK or a NACK fordifferent SPS PDSCHs, respectively.

On the other hand, if different PUCCH resources are allocated fordifferent PDSCHs of different SPS configurations:

Different HAQR-ACK resources may indicate an ACK or a NACK for differentSPS PDSCHs, respectively.

b) If a PUCCH resource for SPS configuration index=N is not explicitlyconfigured, a UE may determine that a PUCCH resource for SPSconfiguration index=N−k (or N+k) is also used for SPS configurationindex=N. Here, k=1 or another integer.

c) When PUCCH configuration (e.g., PUCCH-config) for multicast isconfigured, a PUCCH resource for group common SPS configuration index(s)may be determined based on a PUCCH configuration for multicast (e.g.,PUCCH-config) and a PUCCH resource for UE-specific SPS configurationindex(s) may be determined based on a PUCCH configuration for unicast(e.g., PUCCH-config).

On the other hand, when a PUCCH configuration (e.g., PUCCH-config) formulticast is not configured, a UE may determine that a PUCCH resourcefor group common SPS configuration index(s) is determined based on aPUCCH configuration (e.g., PUCCH-config) for unicast.

2) In the case of group common SPS retransmission, a PUCCH resource maybe allocated by DCI with a CRC scrambled by a G-CS-RNTI.

a) When a UE determines a PUCCH resource, the UE may regard this groupcommon SPS retransmission as a group common PDSCH scheduled by DCI.

b) When a PUCCH configuration (e.g., PUCCH-config) for multicast isconfigured, a UE may determine that a PUCCH resource for group commonSPS retransmission is determined based on a PUCCH configuration (e.g.,PUCCH-config) for multicast.

c) If a PUCCH configuration (e.g., PUCCH-config) for multicast is notconfigured, a UE may determine that a PUCCH resource for group commonSPS retransmission is determined based on a PUCCH configuration forunicast (e.g., PUCCH-config).

When a UE determines a PUCCH resource, a UE may regard this SPSretransmission as a unicast PDSCH (or group common PDSCH).

3) For UE-specific SPS retransmission of a TB initially transmitted by agroup common SPS PDSCH, a PUCCH resource may be allocated by DCIscrambled a CRC by a CS-RNTI.

a) When a UE determines a PUCCH resource, the UE may regard thisUE-specific SPS retransmission as a unicast PDSCH.

Alternatively, when a UE determines a PUCCH resource, the UE may regardthis UE specific SPS retransmission as a group common PDSCH scheduled byDCI.

b) When a PUCCH configuration (e.g., PUCCH-config) for multicast isconfigured, a UE may determine that a PUCCH resource for group commonSPS retransmission is determined based on a PUCCH configuration formulticast (e.g., PUCCH-config).

Alternatively, even if a UE has a PUCCH configuration (e.g.,PUCCH-config) for multicast, the UE may determine that a PUCCH resourcefor group common SPS retransmission is determined based on a PUCCHconfiguration for unicast (e.g., PUCCH-config).

c) If PUCCH-config for multicast is not configured, UE determines thatPUCCH resources for group common SPS retransmssion is determined basedon PUCCH-config for unicast.

When a PUCCH-config for multicast is not configured, a UE determinesthat a PUCCH resource for group common SPS retransmission is determinedbased on PUCCH-config for unicast.

4) Either a NACK only based HARQ-ACK or a UE specific ACK/NACK basedHARQ-ACK may be used for SPS PDSCH retransmission.

I. When transmitting Unicast UCI and one or a plurality of MBSHARQ-ACK(s) together in the same slot or sub-slot according to theseprocesses/methods, a UE may transmit one or more PUCCHs as follows.

When multiple unicast HARQ-ACK(s) of HP for unicast PDSCH(s), Xmulticast HARQ-ACK(s) of HP for multicast PDSCH(s), and Y multicastHARQ-ACK(s) of LP for multicast PDSCH(s) overlap in the same slot, a UEmay transmit PUCCH(s) as follows:

1) Option 1: A UE supporting 2 TDMed PUCCHs may transmit 2 TDMed PUCCHsin the slot (e.g., when a PUCCH configuration for multicast (e.g.,PUCCH-Config) and a PUCCH configuration for unicast (e.g., PUCCH-Config)are separately configured).

a) Option 1-1: A UE may transmit one PUCCH (some of multicast HARQ-ACKsmay be dropped or may not dropped) carrying a separate HARQ-ACK codebookfor multiplexed multicast HARQ-ACK(s) and one PUCCH carrying a separateHARQ-ACK codebook for unicast HARQ-ACK(s).

b) Option 1-2: A UE may transmit one PUCCH (some of multicast HARQ-ACKsmay be dropped or may not dropped) for multiplexed multicast HARQ-ACK(s)and transmit one PUCCH for multiplexed multicast HARQ-ACK(s) and unicastHARQ-ACK(s).

c) In option 1, A UE may transmit as follows:

c-1) A UE may transmit different PUCCHs configured for different cells.For example, a UE may transmit i) one PUCCH for PCell and ii) one PUCCHfor SCell having multicast reception.

c-2) A UE may transmit different PUCCHs configured for differentpriorities. For example, a UE may transmit i) one PUCCH for multiplexingHARQ-ACKs with HP and ii) one PUCCH for multiplexing HARQ-ACKs with LP.

c-3) A UE may transmit configured PUCCHs for a HARQ-ACK and CSI/SR. Forexample, a UE may transmit i) one PUCCH for multiplexingmulticast/unicast HARQ-ACKs, and ii) one PUCCH for multiplexing CSIreporting and SR.

c-4) A UE may transmit PUCCHs for different cast types. For example, aUE may transmit i) one PUCCH for unicast HARQ-ACKs and ii) one PUCCH formulticast HARQ-ACKs.

c-5) A UE may transmit different PUCCHs based on a UE capability or amaximum PUCCH payload size. A UE may transmit i) one PUCCH formultiplexing Z multicast HARQ-ACKs and unicast HARQ-ACKs, and ii) onePUCCH for multiplexing (X+Y−Z) multicast HARQ-ACKs.

Here, Z may be determined based on a UE capability or a maximum PUCCHpayload size. Z multicast HARQ-ACKs may be determined among X multicastHPs and Y multicast LPs based on one or more of the following:

HP may be included in Z multicast HARQ-ACKs in preference to LP.

An earlier PDSCH occasion may be included in Z multicast HARQ-ACKs withpriority.

c-6) A UE may transmit different PUCCHs configured for a non-MBS and anMBS. For example, a UE may transmit i) one PUCCH (i.e., a first PUCCH)for multiplexing unicast HARQ-ACK, CSI reporting, and SR, ii) one PUCCH(i.e., the second PUCCH) for multiplexing of multicast HARQ-ACK (and, ifconfigured, multicast CSI reports).

For example, in the case of a UE supporting two TDMed PUCCHs for unicastand multicast, two PUCCHs can be transmitted in the same slot. In thiscase, REL-15/16 feedback (HARQ-ACK, CSI and/or SR) may be multiplexed ona first PUCCH based on a PUCCH configuration (e.g., PUCCH-config) forunicast excluding multicast HARQ-ACK(s). In a second PUCCH, multipleHARQ-ACK(s) may be multiplexed.

Here, if a first PUCCH and a second PUCCH overlap, they may bemultiplexed into one PUCCH according to the REL-15/16 rule. On the otherhand, if a first PUCCH and a second PUCCH do not overlap, they may betransmitted separately.

In addition, when a PUCCH configuration (e.g., PUCCH-config) formulticast is configured, a second PUCCH may be determined based on aPUCCH configuration (e.g., PUCCH-config) for multicast. On the otherhand, if a PUCCH configuration for multicast (e.g., PUCCH-config) is notconfigured, a second PUCCH for multicast HARQ-ACK may be determinedbased on a PUCCH configuration for unicast (e.g., PUCCH-config).

2) Option 2: A UE that does not support two PUCCHs may transmit only oneof the following PUCCHs (e.g., when a PUCCH configuration (e.g.,PUCCH-Config) for multicast are not separately configured) and drop theremaining PUCCHs.

a) A UE may transmit one of PUCCHs configured for different cells. Forexample, a UE may transmit one of i) one PUCCH for PCell and ii) onePUCCH for multicast-received SCell.

b) A UE may transmit one of PUCCHs configured for different priorities.For example, a UE may transmit one of i) a PUCCH for multiplexingHARQ-ACK(s) with HP, ii) a PUCCH for multiplexing HARQ-ACK(s) with LP.

c) A UE may transmit one of PUCCH(s) configured for HARQ-ACK(s) andCSI/SR. For example, a UE may transmit one of i) a PUCCH formultiplexing multicast/unicast HARQ-ACK(s), and ii) a PUCCH formultiplexing CSI reporting and SR.

d) A UE may transmit one of PUCCHs configured for different cast types.For example, a UE may transmit one of i) a PUCCH for unicast HARQ-ACK(s)and ii) a PUCCH for multicast HARQ-ACK(s).

e) A UE may transmit one of PUCCHs based on a UE capability or a maximumPUCCH payload size. A UE may transmit one of i) one PUCCH formultiplexing Z multicast HARQ-ACK(s) and unicast HARQ-ACK(s), ii) onePUCCH for multiplexing (X+Y−Z) multicast HARQ-ACK(s).

Here, Z may be determined based on a UE capability or a maximum PUCCHpayload size. Z multicast HARQ-ACK(s) may be determined among Xmulticast HP HARQ-ACK(s) and Y multicast LP HARQ-ACK(s) based on one ormore of the following:

P may be included in Z multicast HARQ-ACK(s) in preference to LP.

An earlier PDSCH occasion may be included in Z multicast HARQ-ACK(s)with priority.

f) A UE may transmit one of PUCCHs configured for a non-MBS and an MBS.For example, a UE may transmit i) one PUCCH (i.e., the first PUCCH) formultiplexing of unicast HARQ-ACK(s), CSI reporting and SR and ii) onePUCCH (i.e., the second PUCCH) for multiplexing of multicast HARQ-ACK(and, if configured, multicast CSI reports).

For example, in the case of a UE supporting two TDMed PUCCHs for unicastand multicast, two PUCCHs may be transmitted in the same slot. In thiscase, REL-15/16 feedback (HARQ-ACK, CSI and/or SR) may be multiplexed ona first PUCCH based on a PUCCH configuration (e.g., PUCCH-config) forunicast excluding multicast HARQ-ACK(s). In a second PUCCH, multipleHARQ-ACK(s) may be multiplexed.

Here, if a first PUCCH and a second PUCCH overlap, they may bemultiplexed into one PUCCH according to the REL-15/16 rule. On the otherhand, if a first PUCCH and a second PUCCH do not overlap, they may betransmitted separately.

In addition, when a PUCCH configuration for multicast (e.g.,PUCCH-config) is configured, a second PUCCH may be determined based on aPUCCH configuration for multicast (e.g., PUCCH-config). On the otherhand, if a PUCCH configuration for multicast (e.g., PUCCH-config) is notconfigured, a second PUCCH for multicast HARQ-ACK may be determinedbased on a PUCCH configuration for unicast (e.g., PUCCH-config).

3) Option 3: A UE may drop all or part of multicast HARQ-ACK(s) with LPaccording to a UE capability or a maximum PUCCH payload size.

A UE may transmit one PUCCH by multiplexing Z multicast HARQ-ACK(s) andunicast HARQ-ACK(s).

Here, Z may be determined based on a UE capability or a maximum PUCCHpayload size. Z multicast HARQ-ACK(s) may be determined among Xmulticast HP HARQ-ACK(s) and Y multicast LP HARQ-ACK(s) based on one ormore of the following:

HP may be included in Z multicast HARQ-ACK(s) in preference to LP.

An earlier PDSCH occasion may be included in Z multicast HARQ-ACK(s)with priority.

4) Option 4: A UE may defer all or part of multicast HARQ-ACK(s) to thenext PUCCH transmission (e.g., depending on whether a PUCCHconfiguration for multicast (e.g., PUCCH-Config) and a PUCCHconfiguration for unicast (e.g., PUCCH-Config) are separatelyconfigured) and transmit unicast/multicast remaining HARQ-ACK(s) on aPUCCH in the current slot:

a) This option is applicable only when semi-static PUCCH resources areperiodically configured.

b) Option 4-1: Z multicast HARQ-ACK(s) may be deferred to the next PUCCHtransmission allocated to unicast or other multicast PDSCH. Deferredmulticast HARQ-ACK(s) may be multiplexed with next unicast HARQ-ACK(s)and/or other multicast HARQ-ACK(s).

The next unicast HARQ-ACK(s) in the next PUCCH may not be HP.

Other multicast HARQ-ACK(s) in the next PUCCH may not be HP.

Deferred multicast HARQ-ACK(s) may be deferred until a maximum K valueor the next PUCCH resource.

c) Option 4-2: Z multicast HARQ-ACK(s) may be deferred to the next PUCCHtransmission allocated to another multicast PDSCH (not unicast PDSCH)(e.g., when a PUCCH configuration (e.g., PUCCH-Config) for multicast isseparately configured).

Other multicast HARQ-ACK(s) in the next PUCCH may not be HP.

Deferred multicast HARQ-ACK(s) may be deferred until a maximum K valueor the next PUCCH resource.

d) In option 4, when only some of multicast HARQ-ACK(s) are delayed,

Non-deferred multicast HARQ-ACK(s) may be dropped or multiplexed likeoption 1 or 2.

Non-deferred multicast HARQ-ACK(s) may be bundled like option 5.

e) In option 4, a UE may determine Z multicast HARQ-ACK(s) among Xmulticast HARQ-ACK(s) with HP and Y multicast HARQ-ACK(s) with LP.

HP may prioritize over LP (or only HP may be deferred). Alternatively,LP may prioritize over HP (or only LP may be deferred).

An earlier PDSCH occasion may prioritize. Alternatively, a later PDSCHoccasion may prioritize.

f) If a PUCCH configuration (e.g., PUCCH-Config) for multicast is notseparately configured, a UE cannot defer all or part of multicastHARQ-ACK(s) and may drop them.

5) Option 5: A UE may bundle multicast HARQ-ACK(s) and unicastHARQ-ACK(s).

a) For example, 1 HARQ-ACK bit on a PUCCH may indicate bundling ofmulticast HARQ-ACK(s) and unicast HARQ-ACK(s).

Here, when both multicast HARQ-ACK(s) and unicast HARQ-ACK(s) in abundle correspond to an ACK, a HARQ-ACK bit may indicate an ACK. On theother hand, if at least one of multicast HARQ-ACK(s) and unicastHARQ-ACK(s) in a bundle corresponds to a NACK, a HARQ-ACK bit mayindicate an ACK.

b) If only some of multicast HARQ-ACK(s) are bundled (e.g., with thesame priority):

Non-bundled multicast HARQ-ACK(s) may be multiplexed like option 1 or 2.

Alternatively, non-bundled multicast HARQ-ACK(s) may be dropped as inoption 3.

Alternatively, non-bundled multicast HARQ-ACK(s) may be deferred likeoption 4.

c) Option 5-1: Z multicast HARQ-ACK(s) may be bundled with K HARQ-ACKbits (K<Z)(s).

Here, a UE may transmit one HARQ-ACK codebook through a PUCCH.

Alternatively, a UE may transmit a separate sub-codebook for bundlingHARQ-ACK(s) and a separate sub-codebook for the remaining HARQ-ACK(s) onone PUCCH.

Alternatively, a UE may transmit a separate codebook for bundlingHARQ-ACK(s) and a separate codebook for the remaining HARQ-ACK(s) on twoPUCCHs, respectively.

d) Option 5-2: Z multicast HARQ-ACK(s) and unicast HARQ-ACK(s) may bebundled into K HARQ-ACK bit(s) (e.g., when a PUCCH configuration (e.g.,PUCCH-Config) for multicast is not separately configured).

Here, a UE may transmit one HARQ-ACK codebook through a PUCCH.

Alternatively, a UE may transmit a separate sub-codebook for bundlingHARQ-ACK(s) and a separate sub-codebook for the remaining HARQ-ACKs onone PUCCH.

Alternatively, a UE may transmit a separate codebook for bundlingHARQ-ACK(s) and a separate codebook for the remaining HARQ-ACK(s) on twoPUCCHs, respectively.

e) If only some of multicast HARQ-ACK(s) are bundled in option 5 (e.g.,with the same priority):

Non-bundled multicast HARQ-ACK(s) may be dropped or multiplexed as inoption 1 or 2.

Alternatively, non-bundled multicast HARQ-ACK(s) may be deferred as inoption 4.

J. Meanwhile, for two PUCCH transmissions of each of multicastHARQ-ACK(s) and unicast HARQ-ACK(s) or for multiplexing of multicastHARQ-ACK(s) and unicast HARQ-ACK(s) on one PUCCH, if a PUCCH of N symbolslots is determined for unicast HARQ-ACK(s), it needs to be determinedfor a PUCCH multicast HARQ-ACK(s) of N symbol slots. If a PUCCH of Nsymbol slots cannot be determined for multicast HARQ-ACK(s) (e.g., whena PUCCH of N symbol slots is not configured in a PUCCH configuration formulticast (e.g., PUCCH-config)), multicast HARQ-ACK (s) may be droppedor deferred. Alternatively, when a PUCCH of N symbol slots cannot bedetermined for multicast HARQ-ACK(s) based on a PUCCH configuration(e.g., PUCCH-config) for multicast, a PUCCH of N symbol slots may bedetermined for multicast HARQ-ACK(s) based on a PUCCH configuration forunicast (e.g., PUCCH-config).

For example, for multiplexing (mux) with the same priority, a PUCCH maybe configured so that if unicast corresponds to a subslot, multicastalso corresponds to a subslot, and if unicast corresponds to a slot,multicast also corresponds to a slot. Alternatively, if a mini-slot issupported, a PUCCH may be configured so that if unicast corresponds to 2symbols, multicast also corresponds to 2 symbol subslot, and if unicastcorresponds to 7 symbols, multicast also corresponds to 7 symbol subslot.

8. If decoding of a TB on a PDSCH transmission occasion fails, a UE maytransmit a HARQ NACK to a base station on a PUCCH resources in aconfigured UL CFR (S906 b).

By using a PUCCH resource, a UE may also transmit a HARQ-ACK for otherPDSCH transmissions such as a unicast SPS PDSCH, a dynamic unicastPDSCH, PTP retransmission, and/or a dynamic group common PDSCH. In thiscase, to multiplex a HARQ-ACK on a PUCCH in a (sub)slot for an SPS PDSCHfor multicast, an SPS PDSCH for unicast, a dynamically scheduledmulticast PDSCH, and/or a dynamically scheduled unicast PDSCH, a UE mayconstruct a codebook based on one or more options in step 7 above.

Meanwhile, if a PDSCH aggregation factor (pdsch-AggregationFactor) isconfigured for a G-RNTI or a base station indicates a repetition number(repeat number) in DCI, a TB scheduled by group common DCI may berepeated for the Nth HARQ transmission of a TB within each symbolallocation among each PDSCH aggregation factor (pdsch-AggregationFactor)consecutive slots or among each repetition number (repeat number)consecutive slots.

In the case of a HARQ ACK for slot-based group common PDSCH repetitionof a TB, if a PDSCH aggregation factor (pdsch-AggregationFactor) isconfigured for a G-RNTI or a base station indicates a repetition number(repeat number) in DCI with a CRC scrambled by a G-RNTI, a base stationmay allocate multiple PUCCH resources as follows:

Option 1: Multiple PUCCH resources may be allocated by group common DCIscheduling slot-based group common PDSCH repetition.

Option 2: A periodic PUCCH resource may be allocated to a UE receiving aG-RNTI.

Option 3: A periodic PUCCH may be allocated for G-RNTI(s) or a CFR forwhich group common PDSCH repetition is scheduled.

Here, when an ACK/NACK-based HARQ-ACK is configured, different UEs mayselect different PUCCH resources.

If a UE successfully receives a TB from HARQ process number (HPN) #ibefore slot-based group common PDSCH repetition ends, and if a PUCCHresource for a HARQ-ACK for a TB is available before slot-based groupcommon PDSCH repetition ends, a UE may transmit an ACK for a PUCCHresource before the slot-based group common PDSCH repetition ends.

Option A: A UE may skip ACK transmission in another PUCCH resource afterslot-based group common PDSCH repetition ends. In this option, a UE canreceive another TB from HPN#i.

Option B: A UE may retransmit an ACK in another PUCCH resource aftercompletion of slot-based group common PDSCH repetition.

Option C: A UE may deprioritize ACK transmission in other PUCCHresources after the slot-based group common PDSCH repetition ends.

Additionally, a UE may transmit an ACK in a UE-specific PUCCH resourceallocated for a unicast PDSCH.

Alternatively, a UE may not transmit an ACK in a PUCCH resource beforethe slot-based group common PDSCH repetition ends. In this case, a UEmay transmit a HARQ-ACK through a PUCCH resource indicated by a PRI ofDCI scheduling a group common PDSCH after slot-based group common PDSCHrepetition ends.

If a UE successfully receives a TB (e.g., in the Nth HARQ transmission),and if a UE monitors HARQ retransmission (e.g., N+K th HARQtransmission) of a TB by UE-specific DCI or group common DCI, a UE mayperform one of the following.

Option A: A UE may skip ACK transmission in a PUCCH resource allocatedby DCI.

Option B: A UE may retransmit an ACK in a PUCCH resource allocated byDCI.

Option C: A UE may deprioritize ACK transmission in a PUCCH resourceallocated by DCI.

9. A base station receiving a HARQ NACK with a TCI state may retransmita PDCCH and a PDSCH with a TCI state in a DL CFR configured for TBretransmission. A UE may monitor a group common and/or UE-specific PDCCHwith a TCI state on a search space configured in a DL CFR to receive TBretransmission (S907 b).

A base station may retransmit a TB to only one of UEs in a group by aUE-specific PDCCH, and other UEs may not receive retransmission of a TB(e.g., because the other UEs successfully received the TB).

10. When a UE receives a PDCCH for retransmission of a TB (S908 b), a UEmay receive a PDSCH scheduled by DCI of a

PDCCH (S909 b, S910 b).

If a UE successfully decodes a TB on a PDSCH, based on a mapping betweenan MBS service indicated by DCI and an HPN (HARQ process number) and/orbetween an MBS service indicated by DCI and a short ID(s) (ifavailable), the UE may consider that the decoded TB is associated withan MTCH, an MRB, a TMGI, a G-RNTI and/or a short ID of an MBS service.

11. If decoding of a TB succeeds in a PDSCH transmission occasion, a UEmay transmit a HARQ ACK to a base station through a PUCCH resource in aUL CFR configured according to step 7. On the other hand, if decoding ofa TB on a PDSCH transmission occasion fails, a UE may transmit a HARQNACK to a base station on a PUCCH resource in a configured UL CFR (S911b).

By using a PUCCH resource, a UE may also transmit HARQ-ACKs for otherPDSCH transmissions such as a unicast SPS PDSCH, a dynamic unicastPDSCH, PTP retransmission, and/or a dynamic group common PDSCH. In thiscase, to multiplex HARQ-ACKs on a PUCCH in a (sub)slot for an SPS PDSCHfor multicast, an SPS PDSCH for unicast, a dynamically scheduledmulticast PDSCH, and/or a dynamically scheduled unicast PDSCH, a UE mayconstruct a codebook based on one or more options in step 7 above.

12. Meanwhile, upon collision, a UE may monitor a multicast PDCCH andreceive a multicast PDSCH as follows:

A. If a multicast PUCCH overlaps semi-statically configured unicast DLreception, or

If a multicast PUCCH overlaps semi-statically configured unicast ULtransmission, or

If a multicast PUCCH overlaps with a semi-statically configuredsidelink,

In the case of an MBS SPS HARQ-ACK, a UE may defer or drop a HARQ-ACK.

In the case of an MBS HARQ ACK indicated by a PRI of DCI, a UE maytransmit a HARQ-ACK.

B. If a multicast PUCCH overlaps with dynamically configured unicast DLreception, or

If a multicast PUCCH overlaps with dynamically configured unicast ULtransmission,

A UE may defer or drop a HARQ-ACK (e.g., when a HARQ-ACK is LP or otherTX/RX is HP).

A UE may transmit a HARQ-ACK (e.g., when a HARQ-ACK is HP and otherTX/RX is LP).

C. If a multicast PUCCH overlaps with a dynamic multicast PDSCH,

A UE may drop a HARQ-ACK up to a maximum value of K1 (when multicast isHP).

D. If a multicast PUCCH overlaps with a multicast SPS PDSCH, a UE maydefer or drop a HARQ-ACK.

E. When a UE triggers a RACH, a UE may monitor a group common PDCCH andreceive a group common PDSCH as follows.

A UE may monitor a group common PDCCH after triggering a RACH.

When a RACH is triggered, a UE may suspend monitoring of a group commonPDCCH and reception of a group common PDSCH.

A UE may resume group common PDCCH reception after one of MSG1, MSG2,MSG3, and MSG4 of step 4 RACH or one of MSGA and MSGA of step 2 RACH.

In the case of step 4 RACH, a UE may prioritize MSG1, MSG2, MSG3, andMSG4 over group common PDCCH/PDSCH reception, a group common PDSCH, anda HARQ-ACK.

In the case of step 2 RACH, MSGA and MSGB may be prioritized over groupcommon PDCCH/PDSCH reception, a group common PDSCH and a HARQ-ACK.

A UE may transmit an MBS HARQ-ACK through a PUCCH immediately afterMSG2/B reception (for CF-RACH) or first MSG3 transmission (for CB-RACH).

A UE cannot transmit an MBS HARQ-ACK without UL synchronization.

MSG3 may not be multiplexed with a PUCCH A/N.

A UE may disable a HARQ-ACK before MSG3 (or MSG2/B) and enable aHARQ-ACK after MSG3 (or MSG2/B).

Meanwhile, an example of FIG. 9 is for convenience of description anddoes not limit the scope of the present disclosure. Some step(s)illustrated in FIG. 9 may be omitted depending on circumstances and/orsettings. In addition, a base station and a UE in FIG. 9 are just oneexample, and may be implemented as the device illustrated in FIG. 12below. For example, the processor (102/202) of FIG. 12 can control totransmit and receive channels/signals/data/information, etc.

using the transceiver (106/206) and can also control to storetransmitted or received channels/signals/information/data/information,etc. in the memory (104/204).

A base station may be a general term for an object that transmits andreceives data with a terminal. For example, a base station may be aconcept including one or more transmission points (TPs), one or moretransmission and reception points (TRPs), etc. Also, a TP and/or a TRPmay include a panel of a base station, a transmission and receptionunit, etc. In addition, “TRP” may be replaced with expressions such as apanel, an antenna array, a cell (e.g., macro cell/small cell/pico cell,etc.)/a TP (transmission point), base station (base station, gNB, etc.),etc. As described above, TRPs may be classified according to information(e.g., index, ID) on a CORESET group (or CORESET pool). For example,when one UE is configured to transmit/receive with multiple TRPs (orcells), this may mean that multiple CORESET groups (or CORESET pools)are configured for one UE. Configuration of such a CORESET group (orCORESET pool) may be performed through higher layer signaling (e.g., RRCsignaling, etc.).

Referring to FIG. 9 , signaling between one base station and a UE isconsidered for convenience of explanation, but the correspondingsignaling scheme can be extended and applied to signaling betweenmultiple TRPs and multiple UEs. Alternatively, a base station mayinclude a plurality of TRPs, or may be one cell including a plurality ofTRPs.

FIG. 10 is a diagram illustrating an operation of a UE for a method fortransmitting and receiving HARQ-ACK information according to anembodiment of the present disclosure.

In FIG. 10 , an operation of a UE based on any one or a combination ofthe methods proposed above and one or more (detailed) methods isillustrated. An example of FIG. 10 is for convenience of description anddoes not limit the scope of the present disclosure. Some step(s)illustrated in FIG. 10 may be omitted depending on circumstances and/orsettings. In addition, a UE in FIG. 10 is just one example, and may beimplemented as the device illustrated in FIG. 12 below. For example, theprocessor (102/202) of FIG. 12 can control to transmit and receivechannels/signals/data/information, etc. (e.g., RRC signaling, MAC CE,DCI for UL/DL scheduling, SRS, PDCCH, PDSCH, PUSCH, PUCCH, PHICH, etc.)using the transceiver (106/206) and can also control to storetransmitted or received channels/signals/information/data/information,etc. in the memory (104/204).

A UE receives configuration information related to HARQ-ACK reportingfor a multicast PDSCH from a base station (S1001).

Here, the configuration information may configure one reporting method(mode) of ACK/NACK based HARQ-ACK reporting or NACK-only based HARQ-ACKreporting for each of one or more identifiers configured for a UE. Inother words, for all of one or more identifiers configured for a UE, foreach identifier, one reporting method (mode) of ACK/NACK based HARQ-ACKreporting or NACK-only based HARQ-ACK reporting may be configured.

The UE may be configured with one or more identifiers (i.e., RNTI), andthese one or more identifiers may include one or more G-RNTIs and/or oneor more G-CS-RNTIs and/or one or more C-RNTIs and/or one or moreCS-RNTIs, etc.

Meanwhile, although not shown in FIG. 10 , a UE may further receivecommon frequency resource (CFR) configuration information, one or moregroup common PDSCH (or multicast PDSCH) configuration information(separate from unicast PDSCH), PUCCH configuration information for agroup common PDSCH (or a multicast PDSCH) (separate from PUCCHconfiguration for a unicast PDSCH), one or more search spaceconfiguration information from a base station.

Here, one or more group common PDSCH (or multicast PDSCH) configurationinformation may be configured independently for each CFR or may beconfigured independently for each uplink BWP associated with a CFR.

The above configuration information may be transmitted through a higherlayer message (e.g., an RRC message), and this higher layer message maybe a group common message or a UE-specific message.

A UE receives DCI (e.g., multicast DCI) for scheduling a multicast PDSCHfrom a base station (S1002).

Here, DCI for scheduling a multicast PDSCH may mean DCI with a CRCscrambled by a specific identifier among one or more identifiersconfigured for a UE. That is, it may mean DCI with a CRC scrambled byone G-RNTI (or one G-CS-RNTI) among one or more G-RNTIs and/or one ormore G-CS-RNTIs configured for a UE.

For example, in the case of DCI with a CRC scrambled with a G-RNTI,frequency/time domain resource allocation for a multicast PDSCH, a PUCCHresource indicator (PRI), a PDSCH-to-HARQ_feedback timing indicator(PDSCH-to-HARQ_feedback timing indicator), and a priority indicator,etc. may be included. For example, in the case of DCI with a CRCscrambled with a G-CS-RNTI, activation/retransmission/deactivation of anSPS PDSCH may be indicated.

A UE receives a multicast PDSCH based on DCI (e.g., multicast DCI) froma base station (S1003).

As described above, a multicast PDSCH may correspond to a group commonPDSCH in the case of a PTM method and may correspond to a UE-specificPDSCH in the case of a PTP method.

For example, in the case of DCI with a CRC scrambled by a G-RNTI, a UEmay receive a multicast PDSCH (a group common PDSCH or a UE-specificPDSCH) based on information indicated by DCI. Alternatively, in the caseof DCI with a CRC scrambled by a G-CS-RNTI, a UE can receive a multicastPDSCH (i.e., a group common SPS PDSCH) based on SPS PDSCH configurationinformation configured by higher layer signaling.

A UE transmits HARQ-ACK information for a multicast PDSCH on a PUCCH(referred to as a first PUCCH) to a base station (S1004).

If an ACK/NACK based HARQ-ACK reporting method (mode) is configured fora G-RNTI or a G-CS-RNTI for DCI scheduling the multicast PDSCH, a UE maytransmit HARQ-ACK information including an ACK (in case of success) or aNACK (in case of failure) according to whether decoding of a TB carriedin the multicast PDSCH is successful through a first PUCCH.

On the other hand, if a NACK-only based HARQ-ACK reporting method (mode)is configured for a G-RNTI or a G-CS-RNTI for DCI scheduling themulticast PDSCH, a UE may not transmit HARQ-ACK information includingonly an ACK through a first PUCCH. A UE may transmit only HARQ-ACKinformation including at least NACK other than an ACK or including onlya NACK through a first PUCCH.

Here, a resource of a first PUCCH may be indicated (determined) by a PRIfield value of DCI among a PUCCH resource set configured by PUCCHconfiguration information for a multicast PDSCH.

In addition, when PUCCH configuration information for a multicast PDSCHis configured for a CFR or for an uplink BWP, a resource of the firstPUCCH is configured in the CFR in the uplink BWP based on the PUCCHconfiguration information for the multicast PDSCH.

In addition, when a transmission timing of a plurality of firstHARQ-ACKs for a multicast PDSCH (including HARQ-ACK in the multicastPDSCH) and a transmission timing of a plurality of second HARQ-ACKs fora unicast PDSCH overlap within the same slot, a UE may bundle the firstHARQ-ACKs and the second HARQ-ACKs and transmit them through a singlePUCCH. In this case, indication information indicating that the firstHARQ-ACKs and the second HARQ-ACKs are bundled may be additionallytransmitted through a PUCCH.

Alternatively, when a transmission timing of a plurality of firstHARQ-ACKs for a multicast PDSCH (including HARQ-ACK in the multicastPDSCH) and a transmission timing of a plurality of second HARQ-ACKs fora unicast PDSCH overlap within the same slot, some of both the firstHARQ-ACKs and the second HARQ-ACKs may be transmitted through the firstPUCCH, and the rest may be transmitted through a second PUCCH(conversely, the PUCCHs may be interchanged). For example, HARQ-ACKs forPCell and HARQ-ACKs for SCell may be separated and transmitted throughdifferent PUCCHs. Alternatively, HARQ-ACKs may be classified accordingto high/low priorities and transmitted through different PUCCHs.Alternatively, HARQ-ACKs may be classified according to a cast type(multicast or unicast) and transmitted through different PUCCHs.Alternatively, based on a capability of the UE or a maximum PUCCHpayload size, Z (Z is a natural number) HARQ-ACKs may be transmittedthrough one PUCCH, and the remaining HARQ-ACKs may be transmittedthrough another PUCCH.

In addition, when a transmission timing of a plurality of firstHARQ-ACKs for a multicast PDSCH (including HARQ-ACK in the multicastPDSCH) and a transmission timing of a plurality of second HARQ-ACKs fora unicast PDSCH overlap within the same slot, if a UE can transmit onlya single PUCCH, the UE may drop or defer some HARQ-ACKs.

FIG. 11 is a diagram illustrating an operation of a base station for amethod for transmitting and receiving HARQ-ACK information according toan embodiment of the present disclosure.

In FIG. 11 , an operation of a base station based on any one or acombination of the methods proposed above and one or more (detailed)methods is illustrated. An example of FIG. 11 is for convenience ofdescription and does not limit the scope of the present disclosure. Somestep(s) illustrated in FIG. 11 may be omitted depending on circumstancesand/or settings. In addition, a base station in FIG. 11 is just oneexample, and may be implemented as the device illustrated in FIG. 12below. For example, the processor (102/202) of FIG. 12 can control totransmit and receive channels/signals/data/information, etc.

(e.g., RRC signaling, MAC CE, DCI for UL/DL scheduling, SRS, PDCCH,PDSCH, PUSCH, PUCCH, PHICH, etc.) using the transceiver (106/206) andcan also control to store transmitted or receivedchannels/signals/information/data/information, etc. in the memory(104/204).

A base station transmits configuration information related to HARQ-ACKreporting for a multicast PDSCH to a UE (S1101).

Here, the configuration information may configure one reporting method(mode) of ACK/NACK based HARQ-ACK reporting or NACK-only based HARQ-ACKreporting for each of one or more identifiers configured for a UE. Inother words, for all of one or more identifiers configured for a UE, foreach identifier, one reporting method (mode) of ACK/NACK based HARQ-ACKreporting or NACK-only based HARQ-ACK reporting may be configured.

The UE may be configured with one or more identifiers (i.e., RNTI), andthese one or more identifiers may include one or more G-RNTIs and/or oneor more G-CS-RNTIs and/or one or more C-RNTIs and/or one or moreCS-RNTIs, etc.

Meanwhile, although not shown in FIG. 11 , a base station may furthertransmit common frequency resource (CFR) configuration information, oneor more group common PDSCH (or multicast PDSCH) configurationinformation (separate from unicast PDSCH), PUCCH configurationinformation for a group common PDSCH (or a multicast PDSCH) (separatefrom PUCCH configuration for a unicast PDSCH), one or more search spaceconfiguration information to a UE.

Here, one or more group common PDSCH (or multicast PDSCH) configurationinformation may be configured independently for each CFR or may beconfigured independently for each uplink BWP associated with a CFR.

The above configuration information may be transmitted through a higherlayer message (e.g., an RRC message), and this higher layer message maybe a group common message or a UE-specific message.

A base station transmits DCI (e.g., multicast DCI) for scheduling amulticast PDSCH to a UE (S1102).

Here, DCI for scheduling a multicast PDSCH may mean DCI with a CRCscrambled by a specific identifier among one or more identifiersconfigured for a UE. That is, it may mean DCI with a CRC scrambled byone G-RNTI (or one G-CS-RNTI) among one or more G-RNTIs and/or one ormore G-CS-RNTIs configured for a UE.

For example, in the case of DCI with a CRC scrambled with a G-RNTI,frequency/time domain resource allocation for a multicast PDSCH, a PUCCHresource indicator (PRI), a PDSCH-to-HARQ_feedback timing indicator(PDSCH-to-HARQ_feedback timing indicator), and a priority indicator,etc. may be included. For example, in the case of DCI with a CRCscrambled with a G-CS-RNTI, activation/retransmission/deactivation of anSPS PDSCH may be indicated.

A base station transmits a multicast PDSCH to a UE based on DCI (e.g.,multicast DCI) (S1103).

As described above, a multicast PDSCH may correspond to a group commonPDSCH in the case of a PTM method and may correspond to a UE-specificPDSCH in the case of a PTP method.

For example, in the case of DCI with a CRC scrambled by a G-RNTI, a basestation may transmit a multicast PDSCH (a group common PDSCH or aUE-specific PDSCH) based on information indicated by DCI. Alternatively,in the case of DCI with a CRC scrambled by a G-CS-RNTI, a base stationcan transmit a multicast PDSCH (i.e., a group common SPS PDSCH) based onSPS PDSCH configuration information configured by higher layersignaling.

A base station receives HARQ-ACK information for a multicast PDSCH on aPUCCH (referred to as a first PUCCH) from a UE (S1104).

If an ACK/NACK based HARQ-ACK reporting method (mode) is configured fora G-RNTI or a G-CS-RNTI for DCI scheduling the multicast PDSCH, a UE maytransmit HARQ-ACK information including an ACK (in case of success) or aNACK (in case of failure) according to whether decoding of a TB carriedin the multicast PDSCH is successful through a first PUCCH and a basestation can determine whether or not to decode a TB according to thereceived information.

On the other hand, if a NACK-only based HARQ-ACK reporting method (mode)is configured for a G-RNTI or a G-CS-RNTI for DCI scheduling themulticast PDSCH, a UE may not transmit HARQ-ACK information includingonly an ACK through a first PUCCH. That is, if a base station does notreceive HARQ-ACK information through a first PUCCH, it mayconsider/determine that a UE has successfully decoded a correspondingTB. On the other hand, a UE may transmit only HARQ-ACK informationincluding at least NACK other than an ACK or including only a NACKthrough a first PUCCH, and a base station can determine whether or notto decode a TB according to the received information.

Here, a resource of a first PUCCH may be indicated (determined) by a PRIfield value of DCI among a PUCCH resource set configured by PUCCHconfiguration information for a multicast PDSCH.

In addition, when PUCCH configuration information for a multicast PDSCHis configured for a CFR or for an uplink BWP, a resource of the firstPUCCH is configured in the CFR in the uplink BWP based on the PUCCHconfiguration information for the multicast PDSCH.

In addition, when a transmission timing of a plurality of firstHARQ-ACKs for a multicast PDSCH (including HARQ-ACK in the multicastPDSCH) and a transmission timing of a plurality of second HARQ-ACKs fora unicast PDSCH overlap within the same slot, a base station may receivea bundle of the first HARQ-ACKs and the second HARQ-ACKs through asingle PUCCH. In this case, indication information indicating that thefirst HARQ-ACKs and the second HARQ-ACKs are bundled may be additionallytransmitted through a PUCCH.

Alternatively, when a transmission timing of a plurality of firstHARQ-ACKs for a multicast PDSCH (including HARQ-ACK in the multicastPDSCH) and a transmission timing of a plurality of second HARQ-ACKs fora unicast PDSCH overlap within the same slot, some of both the firstHARQ-ACKs and the second HARQ-ACKs may be transmitted through the firstPUCCH, and the rest may be transmitted through a second PUCCH(conversely, the PUCCHs may be interchanged). For example, HARQ-ACKs forPCell and HARQ-ACKs for SCell may be separated and transmitted throughdifferent PUCCHs. Alternatively, HARQ-ACKs may be classified accordingto high/low priorities and transmitted through different PUCCHs.Alternatively, HARQ-ACKs may be classified according to a cast type(multicast or unicast) and transmitted through different PUCCHs.Alternatively, based on a capability of the UE or a maximum PUCCHpayload size, Z (Z is a natural number) HARQ-ACKs may be transmittedthrough one PUCCH, and the remaining HARQ-ACKs may be transmittedthrough another PUCCH.

In addition, when a transmission timing of a plurality of firstHARQ-ACKs for a multicast PDSCH (including HARQ-ACK in the multicastPDSCH) and a transmission timing of a plurality of second HARQ-ACKs fora unicast PDSCH overlap within the same slot, if a UE can transmit onlya single PUCCH, the UE may drop or defer some HARQ-ACKs, and a basestation can determine whether or not to decode a TB according to thereceived information.

General Device to which the Present Disclosure may be Applied

FIG. 12 is a diagram which illustrates a block diagram of a wirelesscommunication device according to an embodiment of the presentdisclosure.

In reference to FIG. 12 , a first wireless device 100 and a secondwireless device 200 may transmit and receive a wireless signal through avariety of radio access technologies (e.g., LTE, NR).

A first wireless device 100 may include one or more processors 102 andone or more memories 104 and may additionally include one or moretransceivers 106 and/or one or more antennas 108. A processor 102 maycontrol a memory 104 and/or a transceiver 106 and may be configured toimplement description, functions, procedures, proposals, methods and/oroperation flow charts disclosed in the present disclosure. For example,a processor 102 may transmit a wireless signal including firstinformation/signal through a transceiver 106 after generating firstinformation/signal by processing information in a memory 104. Inaddition, a processor 102 may receive a wireless signal including secondinformation/signal through a transceiver 106 and then store informationobtained by signal processing of second information/signal in a memory104. A memory 104 may be connected to a processor 102 and may store avariety of information related to an operation of a processor 102. Forexample, a memory 104 may store a software code including commands forperforming all or part of processes controlled by a processor 102 or forperforming description, functions, procedures, proposals, methods and/oroperation flow charts disclosed in the present disclosure. Here, aprocessor 102 and a memory 104 may be part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE, NR). A transceiver 106 may be connected to aprocessor 102 and may transmit and/or receive a wireless signal throughone or more antennas 108. A transceiver 106 may include a transmitterand/or a receiver. A transceiver 106 may be used together with a RF(Radio Frequency) unit. In the present disclosure, a wireless device maymean a communication modem/circuit/chip.

A second wireless device 200 may include one or more processors 202 andone or more memories 204 and may additionally include one or moretransceivers 206 and/or one or more antennas 208. A processor 202 maycontrol a memory 204 and/or a transceiver 206 and may be configured toimplement description, functions, procedures, proposals, methods and/oroperation flows charts disclosed in the present disclosure. For example,a processor 202 may generate third information/signal by processinginformation in a memory 204, and then transmit a wireless signalincluding third information/signal through a transceiver 206. Inaddition, a processor 202 may receive a wireless signal including fourthinformation/signal through a transceiver 206, and then store informationobtained by signal processing of fourth information/signal in a memory204. A memory 204 may be connected to a processor 202 and may store avariety of information related to an operation of a processor 202. Forexample, a memory 204 may store a software code including commands forperforming all or part of processes controlled by a processor 202 or forperforming description, functions, procedures, proposals, methods and/oroperation flow charts disclosed in the present disclosure. Here, aprocessor 202 and a memory 204 may be part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE, NR). A transceiver 206 may be connected to aprocessor 202 and may transmit and/or receive a wireless signal throughone or more antennas 208. A transceiver 206 may include a transmitterand/or a receiver. A transceiver 206 may be used together with a RFunit. In the present disclosure, a wireless device may mean acommunication modem/circuit/chip.

Hereinafter, a hardware element of a wireless device 100, 200 will bedescribed in more detail. It is not limited thereto, but one or moreprotocol layers may be implemented by one or more processors 102, 202.For example, one or more processors 102, 202 may implement one or morelayers (e.g., a functional layer such as PHY, MAC, RLC, PDCP, RRC,SDAP). One or more processors 102, 202 may generate one or more PDUs(Protocol Data Unit) and/or one or more SDUs (Service Data Unit)according to description, functions, procedures, proposals, methodsand/or operation flow charts included in the present disclosure. One ormore processors 102, 202 may generate a message, control information,data or information according to description, functions, procedures,proposals, methods and/or operation flow charts disclosed in the presentdisclosure. One or more processors 102, 202 may generate a signal (e.g.,a baseband signal) including a PDU, a SDU, a message, controlinformation, data or information according to functions, procedures,proposals and/or methods disclosed in the present disclosure to provideit to one or more transceivers 106, 206. One or more processors 102, 202may receive a signal (e.g., a baseband signal) from one or moretransceivers 106, 206 and obtain a PDU, a SDU, a message, controlinformation, data or information according to description, functions,procedures, proposals, methods and/or operation flow charts disclosed inthe present disclosure.

One or more processors 102, 202 may be referred to as a controller, amicro controller, a micro processor or a micro computer. One or moreprocessors 102, 202 may be implemented by a hardware, a firmware, asoftware, or their combination. In an example, one or moreASICs(Application Specific Integrated Circuit), one or more DSPs(DigitalSignal Processor), one or more DSPDs(Digital Signal Processing Device),one or more PLDs(Programmable Logic Device) or one or more FPGAs(FieldProgrammable Gate Arrays) may be included in one or more processors 102,202. Description, functions, procedures, proposals, methods and/oroperation flow charts disclosed in the present disclosure may beimplemented by using a firmware or a software and a firmware or asoftware may be implemented to include a module, a procedure, afunction, etc. A firmware or a software configured to performdescription, functions, procedures, proposals, methods and/or operationflow charts disclosed in the present disclosure may be included in oneor more processors 102, 202 or may be stored in one or more memories104, 204 and driven by one or more processors 102, 202. Description,functions, procedures, proposals, methods and/or operation flow chartsdisclosed in the present disclosure may be implemented by using afirmware or a software in a form of a code, a command and/or a set ofcommands.

One or more memories 104, 204 may be connected to one or more processors102, 202 and may store data, a signal, a message, information, aprogram, a code, an instruction and/or a command in various forms. Oneor more memories 104, 204 may be configured with ROM, RAM, EPROM, aflash memory, a hard drive, a register, a cash memory, a computerreadable storage medium and/or their combination. One or more memories104, 204 may be positioned inside and/or outside one or more processors102, 202. In addition, one or more memories 104, 204 may be connected toone or more processors 102, 202 through a variety of technologies suchas a wire or wireless connection.

One or more transceivers 106, 206 may transmit user data, controlinformation, a wireless signal/channel, etc. mentioned in methods and/oroperation flow charts, etc. of the present disclosure to one or moreother devices. One or more transceivers 106, 206 may receiver user data,control information, a wireless signal/channel, etc. mentioned indescription, functions, procedures, proposals, methods and/or operationflow charts, etc. disclosed in the present disclosure from one or moreother devices. For example, one or more transceivers 106, 206 may beconnected to one or more processors 102, 202 and may transmit andreceive a wireless signal. For example, one or more processors 102, 202may control one or more transceivers 106, 206 to transmit user data,control information or a wireless signal to one or more other devices.In addition, one or more processors 102, 202 may control one or moretransceivers 106, 206 to receive user data, control information or awireless signal from one or more other devices. In addition, one or moretransceivers 106, 206 may be connected to one or more antennas 108, 208and one or more transceivers 106, 206 may be configured to transmit andreceive user data, control information, a wireless signal/channel, etc.mentioned in description, functions, procedures, proposals, methodsand/or operation flow charts, etc. disclosed in the present disclosurethrough one or more antennas 108, 208. In the present disclosure, one ormore antennas may be a plurality of physical antennas or a plurality oflogical antennas (e.g., an antenna port). One or more transceivers 106,206 may convert a received wireless signal/channel, etc. into a basebandsignal from a RF band signal to process received user data, controlinformation, wireless signal/channel, etc. by using one or moreprocessors 102, 202. One or more transceivers 106, 206 may convert userdata, control information, a wireless signal/channel, etc. which areprocessed by using one or more processors 102, 202 from a basebandsignal to a RF band signal. Therefor, one or more transceivers 106, 206may include an (analogue) oscillator and/or a filter.

Embodiments described above are that elements and features of thepresent disclosure are combined in a predetermined form. Each element orfeature should be considered to be optional unless otherwise explicitlymentioned. Each element or feature may be implemented in a form that itis not combined with other element or feature. In addition, anembodiment of the present disclosure may include combining a part ofelements and/or features. An order of operations described inembodiments of the present disclosure may be changed. Some elements orfeatures of one embodiment may be included in other embodiment or may besubstituted with a corresponding element or a feature of otherembodiment. It is clear that an embodiment may include combining claimswithout an explicit dependency relationship in claims or may be includedas a new claim by amendment after application.

It is clear to a person skilled in the pertinent art that the presentdisclosure may be implemented in other specific form in a scope notgoing beyond an essential feature of the present disclosure.Accordingly, the above-described detailed description should not berestrictively construed in every aspect and should be considered to beillustrative. A scope of the present disclosure should be determined byreasonable construction of an attached claim and all changes within anequivalent scope of the present disclosure are included in a scope ofthe present disclosure.

A scope of the present disclosure includes software ormachine-executable commands (e.g., an operating system, an application,a firmware, a program, etc.) which execute an operation according to amethod of various embodiments in a device or a computer and anon-transitory computer-readable medium that such a software or acommand, etc. are stored and are executable in a device or a computer. Acommand which may be used to program a processing system performing afeature described in the present disclosure may be stored in a storagemedium or a computer-readable storage medium and a feature described inthe present disclosure may be implemented by using a computer programproduct including such a storage medium. A storage medium may include ahigh-speed random-access memory such as DRAM, SRAM, DDR RAM or otherrandom-access solid state memory device, but it is not limited thereto,and it may include a nonvolatile memory such as one or more magneticdisk storage devices, optical disk storage devices, flash memory devicesor other nonvolatile solid state storage devices. A memory optionallyincludes one or more storage devices positioned remotely fromprocessor(s). A memory or alternatively, nonvolatile memory device(s) ina memory include a non-transitory computer-readable storage medium. Afeature described in the present disclosure may be stored in any one ofmachine-readable mediums to control a hardware of a processing systemand may be integrated into a software and/or a firmware which allows aprocessing system to interact with other mechanism utilizing a resultfrom an embodiment of the present disclosure. Such a software or afirmware may include an application code, a device driver, an operatingsystem and an execution environment/container, but it is not limitedthereto.

Here, a wireless communication technology implemented in a wirelessdevice 100, 200 of the present disclosure may include NarrowbandInternet of Things for a low-power communication as well as LTE, NR and6G. Here, for example, an NB-IoT technology may be an example of aLPWAN(Low Power Wide Area Network) technology, may be implemented in astandard of LTE Cat NB1 and/or LTE Cat NB2, etc. and is not limited tothe above-described name. Additionally or alternatively, a wirelesscommunication technology implemented in a wireless device 100, 200 ofthe present disclosure may perform a communication based on a LTE-Mtechnology. Here, in an example, a LTE-M technology may be an example ofa LPWAN technology and may be referred to a variety of names such as aneMTC (enhanced Machine Type Communication), etc. For example, an LTE-Mtechnology may be implemented in at least any one of various standardsincluding 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL(non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type

Communication, and/or 7) LTE M and so on and it is not limited to theabove-described name. Additionally or alternatively, a wirelesscommunication technology implemented in a wireless device 100, 200 ofthe present disclosure may include at least any one of a ZigBee, aBluetooth and a low power wide area network (LPWAN) considering alow-power communication and it is not limited to the above-describedname. In an example, a ZigBee technology may generate PAN(personal areanetworks) related to a small/low-power digital communication based on avariety of standards such as IEEE 802.15.4, etc. and may be referred toas a variety of names.

A method proposed by the present disclosure is mainly described based onan example applied to 3GPP LTE/LTE-A, 5G system, but may be applied tovarious wireless communication systems other than the 3GPP LTE/LTE-A, 5Gsystem.

1-18. (canceled)
 19. A method performed by a user equipment (UE) in awireless communication system, the method comprising: receiving, from abase station, configuration information related to hybrid automaticrepeat and request (HARQ)-acknowledgement (ACK) reporting for amulticast physical downlink shared channel (PDSCH), wherein based on theconfiguration information, ACK/negative ACK (NACK) based HARQ-ACKreporting or NACK-only based HARQ-ACK reporting is configured for agroup-radio network temporary identifier (G-RNTI); receiving, from thebase station, downlink control information (DCI) with a cyclicredundancy check (CRC) scrambled by the G-RNTI; receiving, from the basestation, the multicast PDSCH based on the DCI; and based on NACK-onlybased HARQ-ACK reporting being configured for the G-RNTI, transmitting,to the base station, HARQ-ACK information for the multicast PDSCH on afirst physical uplink control channel (PUCCH).
 20. The method of claim19, wherein based on NACK-only based HARQ-ACK reporting being configuredfor the G-RNTI, the first PUCCH that includes only the HARQ-ACKinformation with an ACK is not transmitted.
 21. The method of claim 19,further comprising: receiving PUCCH configuration information for themulticast PDSCH, wherein a resource of the first PUCCH is determined bya PUCCH resource indicator (PRI) in the DCI among a PUCCH resource setconfigured by the PUCCH configuration information.
 22. The method ofclaim 21 wherein the PUCCH configuration information for the multicastPDSCH is configured for each common frequency resource (CFR) or for eachuplink bandwidth part (BWP) associated with the CFR.
 23. The method ofclaim 22, wherein the resource of the first PUCCH is configured in theCFR in the uplink BWP based on the PUCCH configuration information forthe multicast PDSCH.
 24. The method of claim 19, wherein based on aplurality of first HARQ-ACKs including the HARQ-ACK information for amulticast PDSCH and a plurality of second HARQ-ACKs for a unicast PDSCHbeing overlapped in the same slot, the first HARQ-ACKs and the secondHARQ-ACKs are bundled and transmitted through the first PUCCH.
 25. Themethod of claim 24, wherein information indicating bundling of the firstHARQ-ACKs and the second HARQ-ACKs is transmitted through the firstPUCCH.
 26. The method of claim 19, wherein based on a plurality of firstHARQ-ACKs including the HARQ-ACK information for a multicast PDSCH and aplurality of second HARQ-ACKs for a unicast PDSCH being overlapped inthe same slot, some of the first HARQ-ACKs and the second HARQ-ACKs aretransmitted through the first PUCCH, and the rest are transmittedthrough a second PUCCH.
 27. The method of claim 26, wherein HARQ-ACKsfor a primary cell (PCell) are transmitted through a first PUCCH, andHARQ-ACKs for a secondary cell (SCell) are transmitted through a secondPUCCH.
 28. The method of claim 26, wherein HARQ-ACKs with high priorityare transmitted through a first PUCCH, and HARQ-ACKs with low priorityare transmitted through a second PUCCH.
 29. The method of claim 26,wherein the first HARQ-ACKs are transmitted through a first PUCCH, andthe second HARQ-ACKs are transmitted through a second PUCCH.
 30. Themethod of claim 26, wherein based on a capability of the UE or a maximumPUCCH payload size, Z (Z is a natural number) HARQ-ACKs among the firstHARQ-ACKs and the second HARQ-ACKs are transmitted through the firstPUCCH and the remaining HARQ-ACKs are transmitted through the secondPUCCH.
 31. A user equipment (UE) operating in a wireless communicationsystem, the UE comprising: at least one transceiver for transmitting andreceiving a wireless signal; and at least one processor for controllingthe at least one transceiver, wherein the at least one processorconfigured to: receive, from a base station, configuration informationrelated to hybrid automatic repeat and request (HARQ)-acknowledgement(ACK) reporting for a multicast physical downlink shared channel(PDSCH), wherein based on the configuration information, ACK/negativeACK (NACK) based HARQ-ACK reporting or NACK-only based HARQ-ACKreporting is configured for a group-radio network temporary identifier(G-RNTI); receive, from the base station, downlink control information(DCI) with a cyclic redundancy check (CRC) scrambled by the G-RNTI;receive, from the base station, the multicast PDSCH based on the DCI;and based on NACK-only based HARQ-ACK reporting being configured for theG-RNTI, transmit, to the base station, HARQ-ACK information for themulticast PDSCH on a first physical uplink control channel (PUCCH). 32.A base station operating in a wireless communication system, the basestation comprising: at least one transceiver for transmitting andreceiving a wireless signal; and at least one processor for controllingthe at least one transceiver, wherein the at least one processorconfigured to: transmit, to a user equipment (UE), configurationinformation related to hybrid automatic repeat and request(HARQ)-acknowledgement (ACK) reporting for a multicast physical downlinkshared channel (PDSCH), wherein based on the configuration information,ACK/negative ACK (NACK) based HARQ-ACK reporting or NACK-only basedHARQ-ACK reporting is configured for a group-radio network temporaryidentifier (G-RNTI); transmit, to the UE, downlink control information(DCI) with a cyclic redundancy check (CRC) scrambled by the G-RNTI;transmit, to the UE, the multicast PDSCH based on the DCI; and based onNACK-only based HARQ-ACK reporting being configured for the G-RNTI,receive, from the UE, HARQ-ACK information for the multicast PDSCH on afirst physical uplink control channel (PUCCH).